Nervous System

List three parts of the brain and their function

Discuss the role of the nervous system
Discuss the interaction between hormones and behavior.
Summarize the nature vs nurture debate

Explain epigenetics

Here below is the PDF of the EBook.

This information can be found on Page 137-141 (Nervous System), Pg. 150 (Interaction Between Hormones and Behavior), Pg.163 (The 3 parts of the Brain (frontal, parietal, temporal lobes), Pgs.179-182 (Nature and Nurture), Pgs. 189-190 (Epigenetics)

It is not a long assignment, it is just little information on each.

Here is an Example of what I need:

”
List three parts of the brain and their function

– The frontal lobes are important for voluntary movement, expressive language and for managing higher level executive functions. Executive functions refer to a collection of cognitive skills including the capacity plan, organize, initiate, self-monitor and control one’s responses in order to achieve a goal.

– The parietal lobe is vital for sensory perception and integration, including the management of taste, hearing, sight, touch, and smell. It is home to the brain’s primary somatic sensory cortex, a region where the brain interprets input from other areas of the body.

– The temporal lobes sit behind the ears and are the second largest lobe. They are most commonly associated with processing auditory information and with the ding encouragement.

Discuss the role of the nervous system

– The nervous system is the major controlling, regulatory, and communicating system in the body. It is the center of all mental activity including thought, learning and memory. Together with the endocrine system, the nervous system is responsible for regulating and maintaining homeostasis.

Interaction Between Hormones and the Behavior:

– They are very interesting to me because ever since a baby is born the genders are defined by colors just like gender reveals and how since the baby is a boy they dress him up in blueish colors and girls otherwise with pink. but like with the lecture of the monkeys where they don’t have that influence on them and yet due to the hormones in males or females the male monkeys chose male toys such as balls and trucks meanwhile female monkeys chose female toys such as dolls.

Summarize the nature vs nurture debate

From what I gathered from the reading on Lumen. There is a stronger correlation between genetics, suggesting a stronger leaning towards the “nature” stance in the debate. However, it is also important to keep in mind that nurture (and/or environment/social expectations) can also have some impact on a person’s decisions making skills and actions.

Explain epigenetics

-Epigenetics is the study of how your behaviors and environment can cause changes that affect the way your genes work. Unlike genetics changes, epigenetic changes are reversible and do not change your DNA sequence, but they can change how your body read a DNA sequence.”

Introduction to Psychology
Introduction to Psychology
Lumen Learning
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Except where expressly noted otherwise, the contents of this course are based on materials originally published by OpenStax
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CONTENTS
Course ContentsCourse Contents …………………………………………………………………………………………………………………………………………………………………………………………………………………….. 77
• About This Course …………………………………………………………………………………………………………………………… 7
• Course Contents at a Glance ……………………………………………………………………………………………………………. 8
• Learning Outcomes ……………………………………………………………………………………………………………………….. 11
Module 1: Psychological FoundationsModule 1: Psychological Foundations ………………………………………………………………………………………………………………………………………………………… 1616
• Why It Matters: Psychological Foundations……………………………………………………………………………………….. 16
• The History of Psychology ………………………………………………………………………………………………………………. 20
• The History of Psychology Continued……………………………………………………………………………………………….. 31
• Domains in Psychology ………………………………………………………………………………………………………………….. 39
• Careers in Psychology……………………………………………………………………………………………………………………. 54
• Putting It Together: Psychological Foundations …………………………………………………………………………………. 60
• Discussion: Foundations of Psychology ……………………………………………………………………………………………. 64
Module 2: Psychological ResearchModule 2: Psychological Research ……………………………………………………………………………………………………………………………………………………………….. 6666
• Why It Matters: Psychological Research …………………………………………………………………………………………… 66
• The Scientific Method …………………………………………………………………………………………………………………….. 69
• Descriptive Research……………………………………………………………………………………………………………………… 79
• Correlational Research …………………………………………………………………………………………………………………… 89
• Experiments………………………………………………………………………………………………………………………………….. 95
• Statistical Thinking……………………………………………………………………………………………………………………….. 102
• How to Read Research…………………………………………………………………………………………………………………. 116
• Psych in Real Life: Brain Imaging and Messy Science………………………………………………………………………. 125
• Putting It Together: Psychological Research……………………………………………………………………………………. 133
• Discussion: Research in Psychology………………………………………………………………………………………………. 134
Module 3: BiopsychologyModule 3: Biopsychology ………………………………………………………………………………………………………………………………………………………………………………………. 135135
• Why It Matters: Biopsychology ………………………………………………………………………………………………………. 135
• Neural Communication …………………………………………………………………………………………………………………. 137
• The Nervous System and Endocrine System …………………………………………………………………………………… 142
• Parts of the Brain …………………………………………………………………………………………………………………………. 152
• The Limbic System and Other Brain Areas ……………………………………………………………………………………… 166
• Brain Imaging………………………………………………………………………………………………………………………………. 174
• Lateralization and Neuroplasticity…………………………………………………………………………………………………… 178
• Nature and Nurture ………………………………………………………………………………………………………………………. 179
• Gene-Environment Interactions ……………………………………………………………………………………………………… 189
• Putting It Together: Biopsychology …………………………………………………………………………………………………. 193
• Discussion: Biopsychology ……………………………………………………………………………………………………………. 195
Module 4: Sensation and PerceptionModule 4: Sensation and Perception ………………………………………………………………………………………………………………………………………………………. 196196
• Why It Matters: Sensation and Perception ………………………………………………………………………………………. 196
• Sensation and Perception……………………………………………………………………………………………………………… 200
• Vision …………………………………………………………………………………………………………………………………………. 212
• Hearing ………………………………………………………………………………………………………………………………………. 227
• Taste and Smell…………………………………………………………………………………………………………………………… 237
• Touch and Pain……………………………………………………………………………………………………………………………. 240
• The Vestibular Sense …………………………………………………………………………………………………………………… 248
• Perception…………………………………………………………………………………………………………………………………… 251
• Illusions………………………………………………………………………………………………………………………………………. 263
• Putting It Together: Sensation and Perception …………………………………………………………………………………. 274
• Discussion: Sensation and Perception ……………………………………………………………………………………………. 276
Module 5: State of ConsciousnessModule 5: State of Consciousness ……………………………………………………………………………………………………………………………………………………………… 277277

• Why It Matters: States of Consciousness ………………………………………………………………………………………… 277
• Consciousness and Biological Rhythms………………………………………………………………………………………….. 285
• Psych in Real Life: Consciousness and Blindsight ……………………………………………………………………………. 299
• Sleep and Sleep Stages ……………………………………………………………………………………………………………….. 305
• Dreams and Dreaming………………………………………………………………………………………………………………….. 318
• Sleep Problems and Disorders ………………………………………………………………………………………………………. 321
• Drugs and Consciousness…………………………………………………………………………………………………………….. 327
• Hypnosis and Meditation ………………………………………………………………………………………………………………. 339
• Putting It Together: States of Consciousness…………………………………………………………………………………… 342
• Discussion: States of Consciousness……………………………………………………………………………………………… 344
Module 6: LearningModule 6: Learning………………………………………………………………………………………………………………………………………………………………………………………………………… 345345
• Why It Matters: Learning……………………………………………………………………………………………………………….. 345
• What Is Learning?………………………………………………………………………………………………………………………… 348
• Classical Conditioning ………………………………………………………………………………………………………………….. 351
• Operant Conditioning……………………………………………………………………………………………………………………. 364
• Reinforcement Schedules……………………………………………………………………………………………………………… 373
• Latent Learning……………………………………………………………………………………………………………………………. 379
• Observational Learning…………………………………………………………………………………………………………………. 387
• Putting It Together: Learning …………………………………………………………………………………………………………. 395
• Discussion: Learning ……………………………………………………………………………………………………………………. 396
Module 7: MemoryModule 7: Memory………………………………………………………………………………………………………………………………………………………………………………………………………….. 397397
• Why It Matters: Memory………………………………………………………………………………………………………………… 397
• Memory Encoding………………………………………………………………………………………………………………………… 401
• Storage ………………………………………………………………………………………………………………………………………. 406
• Retrieval……………………………………………………………………………………………………………………………………… 413
• Parts of the Brain Involved with Memory …………………………………………………………………………………………. 417
• Amnesia and Forgetting………………………………………………………………………………………………………………… 423
• Flashbulb Memories …………………………………………………………………………………………………………………….. 432
• Eyewitness Testimony and Memory Construction…………………………………………………………………………….. 432
• Ways to Enhance Memory…………………………………………………………………………………………………………….. 439
• Putting It Together: Memory ………………………………………………………………………………………………………….. 446
• Discussion: Memory …………………………………………………………………………………………………………………….. 447
Module 8: Thinking, Language, and IntelligenceModule 8: Thinking, Language, and Intelligence ………………………………………………………………………………………………………………………… 449449
• Why It Matters: Thinking and Intelligence………………………………………………………………………………………… 449
• What Is Cognition? ………………………………………………………………………………………………………………………. 454
• Solving Problems…………………………………………………………………………………………………………………………. 461
• Psych in Real Life: Choice Blindness ……………………………………………………………………………………………… 477
• Language and Language Use ……………………………………………………………………………………………………….. 485
• Language Development………………………………………………………………………………………………………………… 491
• Intelligence and Creativity……………………………………………………………………………………………………………… 497
• Measures of Intelligence……………………………………………………………………………………………………………….. 506
• The Source of Intelligence …………………………………………………………………………………………………………….. 514
• Putting It Together: Thinking and Intelligence ………………………………………………………………………………….. 520
• Discussion: Thinking and Intelligence……………………………………………………………………………………………… 521
Module 9: Emotion and MotivationModule 9: Emotion and Motivation ……………………………………………………………………………………………………………………………………………………………… 522522
• Why It Matters: Emotion and Motivation ………………………………………………………………………………………….. 522
• Motivation …………………………………………………………………………………………………………………………………… 530
• Psych in Real Life: Growth Mindsets ………………………………………………………………………………………………. 553
• Hunger and Eating……………………………………………………………………………………………………………………….. 567
• Sexual Behavior…………………………………………………………………………………………………………………………… 577
• Emotion………………………………………………………………………………………………………………………………………. 588
• Expressing and Recognizing Emotion …………………………………………………………………………………………….. 594

• Putting It Together: Motivation and Emotion…………………………………………………………………………………….. 601
• Discussion: Motivation and Emotion……………………………………………………………………………………………….. 602
Module 10: Lifespan DevelopmentModule 10: Lifespan Development ……………………………………………………………………………………………………………………………………………………………… 603603
• Why It Matters: Introduction to Lifespan Development ………………………………………………………………………. 603
• What Is Lifespan Development?…………………………………………………………………………………………………….. 611
• Psychosexual and Psychosocial Theories of Development ……………………………………………………………….. 618
• Cognitive Development…………………………………………………………………………………………………………………. 622
• Moral Development………………………………………………………………………………………………………………………. 627
• Prenatal Development ………………………………………………………………………………………………………………….. 639
• Childhood……………………………………………………………………………………………………………………………………. 645
• Adolescence ……………………………………………………………………………………………………………………………….. 655
• Adulthood……………………………………………………………………………………………………………………………………. 661
• Death and Dying ………………………………………………………………………………………………………………………….. 665
• Putting It Together: Lifespan Development ……………………………………………………………………………………… 667
• Discussion: Lifespan Development…………………………………………………………………………………………………. 668
Module 11: PersonalityModule 11: Personality ……………………………………………………………………………………………………………………………………………………………………………………………… 670670
• Why It Matters: Personality……………………………………………………………………………………………………………. 670
• Personality and the Psychodynamic Perspective ……………………………………………………………………………… 676
• Neo-Freudians: Adler, Erikson, Jung, and Horney ……………………………………………………………………………. 689
• Explaining Personality: Learning and Humanistic Approaches …………………………………………………………… 695
• Explaining Personality: Biological Approaches and Trait Theories………………………………………………………. 703
• Personality Assessment ……………………………………………………………………………………………………………….. 716
• Psych in Real Life: Blirtatiousness, Questionnaires, and Validity ………………………………………………………… 731
• Resource: Personality Tests………………………………………………………………………………………………………….. 741
• Putting It Together: Personality ……………………………………………………………………………………………………… 742
• Discussion: Personality…………………………………………………………………………………………………………………. 743
Module 12: Social PsychologyModule 12: Social Psychology ………………………………………………………………………………………………………………………………………………………………………… 745745
• Why It Matters: Social Psychology …………………………………………………………………………………………………. 745
• Social Psychology and Influences on Behavior ………………………………………………………………………………… 753
• Social Norms and Scripts ……………………………………………………………………………………………………………… 760
• Attitudes and Persuasion………………………………………………………………………………………………………………. 765
• Group Behavior……………………………………………………………………………………………………………………………. 775
• The Bystander Effect and Altruism …………………………………………………………………………………………………. 786
• Attraction and Love………………………………………………………………………………………………………………………. 792
• Psych in Real Life: Love and Pain ………………………………………………………………………………………………….. 807
• Prejudice and Discrimination …………………………………………………………………………………………………………. 816
• Aggression………………………………………………………………………………………………………………………………….. 824
• Putting It Together: Social Psychology ……………………………………………………………………………………………. 827
• Discussion: Social Psychology ………………………………………………………………………………………………………. 830
Module 13: Stress, Lifestyle, and HealthModule 13: Stress, Lifestyle, and Health ……………………………………………………………………………………………………………………………………………… 831831
• Why It Matters: Stress, Lifestyle, and Health ……………………………………………………………………………………. 831
• Stress…………………………………………………………………………………………………………………………………………. 844
• Stressors…………………………………………………………………………………………………………………………………….. 857
• Stress and Illness ………………………………………………………………………………………………………………………… 865
• Regulating Stress ………………………………………………………………………………………………………………………… 877
• Positive Psychology……………………………………………………………………………………………………………………… 886
• Psych in Real Life: Habits……………………………………………………………………………………………………………… 898
• Putting It Together: Stress, Lifestyle, and Health ……………………………………………………………………………… 908
• Discussion: Stress, Lifestyle, and Health…………………………………………………………………………………………. 910
Module 14: Psychological DisordersModule 14: Psychological Disorders ………………………………………………………………………………………………………………………………………………………… 911911
• Why It Matters: Psychological Disorders …………………………………………………………………………………………. 911

• Introduction to Psychological Disorders…………………………………………………………………………………………… 925
• Anxiety Disorders…………………………………………………………………………………………………………………………. 937
• OCD and PTSD …………………………………………………………………………………………………………………………… 946
• Mood Disorders …………………………………………………………………………………………………………………………… 954
• Schizophrenia and Dissociative Disorders ………………………………………………………………………………………. 966
• Personality Disorders……………………………………………………………………………………………………………………. 976
• Childhood Disorders …………………………………………………………………………………………………………………….. 985
• Review: Classifying Psychological Disorders …………………………………………………………………………………… 992
• Putting It Together: Psychological Disorders……………………………………………………………………………………. 994
• Discussion: Psychological Disorders ………………………………………………………………………………………………. 995
Module 15: Therapy and TreatmentModule 15: Therapy and Treatment ………………………………………………………………………………………………………………………………………………………….. 996996
• Why It Matters: Therapy and Treatment ………………………………………………………………………………………….. 996
• Mental Health Treatment: Then and Now………………………………………………………………………………………. 1003
• Types of Treatment and Psychoanalysis……………………………………………………………………………………….. 1012
• Cognitive-Behavioral Therapy ……………………………………………………………………………………………………… 1016
• Humanistic Therapy and Other Treatments……………………………………………………………………………………. 1023
• Psych in Real Life: Reconsolidation ……………………………………………………………………………………………… 1040
• Treatment Modalities ………………………………………………………………………………………………………………….. 1049
• Putting It Together: Treatment and Therapy…………………………………………………………………………………… 1058
• Discussion: Therapy and Treatment……………………………………………………………………………………………… 1059
Module 16: Industrial-Organizational PsychologyModule 16: Industrial-Organizational Psychology ………………………………………………………………………………………………………………….10611061
• Why It Matters: Industrial-Organizational Psychology ……………………………………………………………………… 1061
• Industrial-Organizational Psychology ……………………………………………………………………………………………. 1067
• Selecting Employees ………………………………………………………………………………………………………………….. 1074
• Job Satisfaction …………………………………………………………………………………………………………………………. 1086
• Leadership and Organization……………………………………………………………………………………………………….. 1091
• Human Factors Psychology and Workplace Design………………………………………………………………………… 1097
• Putting It Together: Industrial-Organizational Psychology ………………………………………………………………… 1101
• Discussion: Industrial-Organizational Psychology …………………………………………………………………………… 1103

COURSE CONTENTS
ABOUT THIS COURSE
This comprehensive, ready-to-adopt Introduction to Psychology course provides thorough coverage of all topics
covered in a typical introductory course, including biological psychology, cognitive psychology, developmental
psychology, social and personality psychology, and mental and physical health.
The course is organized around the recently recommended model from the American Psychological Association,
which encompasses the five psychological domains, or pillars: biological psychology, cognitive psychology,
developmental psychology, social and personality psychology, and mental and physical health psychology (see
“Strengthening Introductory Psychology: A New Model for Teaching the Introductory Course”).
With the OpenStax Psychology textbook as a foundation, this contains other material curated by Lumen Learning
and created by Patrick Carroll of the University of Texas at Austin. The course enriches learning with frequent
application, curated videos, selected NOBA content, and interactive learning activities to foster practical skills.
Engaging “Psychology in Real Life” features use recent research to help students think critically about
experimental design.
What’s New?
We believe in making continual improvements to the course in order to enhance and facilitate student learning.
This newest version of the course includes additional Psych in Real Life pages, which provide learners with the
opportunity to think deeply about relevant psychological research. These 2019 additions include:
• Psych in Real Life: Brain Imaging and Messy Science
◦ Dive into a psychological research article (McCabe and Castel) and learn more about the
replication crisis
• Psych in Real Life: Consciousness and Blindsight
◦ Describe unconscious perception as it relates to blindsight
• Psych in Real Life: Choice Blindness
◦ Understand decision-making processes and choice blindness, based on research done by
Johannson and Hall
• Psych in Real Life: Love and Pain
◦ Look at two studies (Sarah Master and Jarred Younger) related to romantic love and the
experience of pain
• Psych in Real Life: Blirtatiousness, Questionnaires, and Validity
◦ Understand how personality tests are created, then examine how validity is measured
• Psych in Real Life: Growth Mindsets
◦ Dive into Dweck’s research on growth mindsets
• Psych in Real Life: Reconsolidation
◦ Understand how memory reconsolidation can be used as a therapy technique
• Psych in Real Life: Habits
◦ Look at research on habitual behavior and popcorn eating by Wendy Wood and David Neal
In additional to these new pages, there are also several new assignments options. We have also used data to find
areas in the course in need of further clarification or interactives, such as this one about reliability and validity.

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About Lumen
Lumen Learning’s mission is to enable unprecedented learning for all students.
We do this by using open educational resources (OER) to create well-designed and low-cost course materials
that replace expensive textbooks. Because learning is about more than affordability and access, we also apply
learning science insights and efficacy research to develop learning activities that are engineered to improve
subject mastery, course completion and retention.
If you’d like to connect with us to learn more about adopting this course, please Contact Us.
You can also make an appointment for OER Office Hours to connect virtually with a live Lumen expert about any
question you may have.
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COURSE CONTENTS AT A GLANCE
The following list shows the module-level topics for the course. To see all of the course pages, visit the Table of
Contents.
Module 1: Psychological Foundations
• The History of Psychology
• Domains in Psychology
• Careers in Psychology
Module 2: Psychological Research
• The Scientific Method
• Descriptive Research
• Correlational Research
• Experiments
• Statistical Thinking
• How to Read Research
• Biological Psychology Domain

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Office Hours

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Module 3: Biopsychology
• Neural Communication
• The Nervous System and Endocrine System
• Parts of the Brain
• The Limbic System and Other Brain Areas
• Brain Imaging
• Nature and Nurture
• Gene-Environment Interactions
Module 4: State of Consciousness
• Consciousness and Biological Rhythms
• Sleep and Sleep Stages
• Dreams and Dreaming
• Sleep Problems and Disorders
• Drugs and Consciousness
• Hypnosis and Meditation
• Cognitive Psychology Domain
Module 5: Sensation and Perception
• Sensation and Perception
• Vision
• Hearing
• Taste and Smell
• Touch and Pain
• The Vestibular Sense
• Perception
• Illusions
Module 6: Thinking and Intelligence
• What Is Cognition?
• Solving Problems
• Language and Language Use
• Language Development
• Intelligence and Creativity
• Measures of Intelligence
• The Source of Intelligence
Module 7: Memory
• Memory Encoding
• Storage
• Retrieval
• Parts of the Brain Involved with Memory
• Amnesia and Forgetting
• Eyewitness Testimony and Memory Construction
• Ways to Enhance Memory
• Developmental Psychology Domain

Module 8: Learning
• What Is Learning?
• Classical Conditioning
• Operant Conditioning
• Reinforcement Schedules
• Latent Learning
• Observational Learning
Module 9: Lifespan Development
• What Is Lifespan Development?
• Psychosexual and Psychosocial Theories of Development
• Cognitive Development
• Moral Development
• Prenatal Development
• Childhood
• Adolescence
• Adulthood
• Death and Dying
• Social and Personality Psychology Domain
Module 10: Social Psychology
• Social Psychology and Influences on Behavior
• Social Norms and Scripts
• Attitudes and Persuasion
• Group Behavior
• The Bystander Effect and Altruism
• Attraction and Love
• Prejudice and Discrimination
• Aggression
Module 11: Personality
• Personality and the Psychodynamic Perspective
• Neo-Freudians: Adler, Erikson, Jung, and Horney
• Explaining Personality: Learning and Humanistic Approaches
• Explaining Personality: Biological Approaches and Trait Theories
• Personality Assessment
Module 12: Emotion and Motivation
• Motivation
• Hunger and Eating
• Sexual Behavior
• Emotion
• Expressing and Recognizing Emotion
Module 13: Industrial-Organizational Psychology
• Industrial-Organizational Psychology
• Selecting Employees

• Job Satisfaction
• Leadership and Organization
• Human Factors Psychology and Workplace Design
• Mental and Physical Health Domain
Module 14: Psychological Disorders
• Introduction to Psychological Disorders
• Anxiety Disorders
• OCD and PTSD
• Mood Disorders
• Schizophrenia and Dissociative Disorders
• Personality Disorders
• Childhood Disorders
Module 15: Therapy and Treatment
• Mental Health Treatment: Then and Now
• Types of Treatment and Psychoanalysis
• Cognitive-Behavioral Therapy
• Humanistic Therapy and Other Treatments
• Treatment Modalities
Module 16: Stress, Lifestyle, and Health
• Stress
• Stressors
• Stress and Illness
• Regulating Stress
• Positive Psychology
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LEARNING OUTCOMES

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The content, assignments, and assessments for this course are aligned to the following learning outcomes. A full
list of course learning outcomes can be viewed here: Complete Learning Outcomes.
This course provides coverage for the broad range of learning outcomes that may be taught in introductory
psychology courses. With the goal of supporting faculty in the selection of content for their courses, we have
organized this course around the 5 pillars, or domains, of psychology as recently recommended by the APA:
biological pillar, cognitive pillar, developmental pillar, social and personality pillar, mental and physical health
pillar.
While we hope that organizing the modules in this fashion proves helpful to faculty, faculty have
complete freedom to select and organize modules for their course as they choose, as modules may easily be
reorganized.
• Module 1: Psychological Foundations
◦ Describe the evolution of psychology and the major pioneers in the field
◦ Identify the various approaches, fields, and subfields of psychology along with their major
concepts and important figures
◦ Describe the value of psychology and possible careers paths for those who study psychology
• Module 2: Psychological Research
◦ Define and apply the scientific method to psychology
◦ Describe the strengths and weaknesses of descriptive, experimental, and correlational research
◦ Define basic elements of a statistical investigation
Biological Psychology Domain
• Module 3: Biopsychology
◦ Identify the basic structures of a neuron, the function of each structure, and how messages
travel through the neuron
◦ Describe the role of the nervous system and endocrine systems
◦ Identify and describe the parts of the brain

https://docs.google.com/spreadsheets/d/1462ht4T8P-IG7FgwM5v0HxasQayZAzrOTAX-baBeots/edit#gid=1071993608

◦ Explain how nature, nurture, and epigenetics influence personality and behavior
• Module 4: State of Consciousness
◦ Describe consciousness and biological rhythms
◦ Describe what happens to the brain and body during sleep
◦ Explain how drugs affect consciousness
Cognitive Psychology Domain
• Module 5: Sensation and Perception
◦ Differentiate between sensation and perception
◦ Explain the process of vision and how people see color and depth
◦ Explain the basics of hearing
◦ Describe the basic anatomy and functions of taste, smell, touch, pain, and the vestibular sense
◦ Define perception and give examples of gestalt principles and multimodal perception
• Module 6: Thinking and Intelligence
◦ Describe cognition and problem-solving strategies
◦ Describe language acquisition and the role language plays in communication and thought
◦ Describe intelligence theories and intelligence testing
• Module 7: Memory
◦ Explain the process of memory
◦ Explain and give examples of forgetting and memory failure
◦ Recognize and apply memory-enhancing strategies
Developmental Psychology Domain
• Module 8: Learning
◦ Explain learning and the process of classical conditioning
◦ Explain operant conditioning, reinforcement, and punishment
◦ Describe latent learning and observational learning
• Module 9: Lifespan Development
◦ Compare and contrast theories lifespan development theories
◦ Explain the physical, cognitive, and emotional development that occurs from infancy through
childhood
◦ Describe physical, cognitive, and emotional development in adolescence and adulthood

Social and Personality Psychology Domain
• Module 10: Social Psychology
◦ Recognize aspects of social psychology, including the fundamental attribution error, biases,
social roles, and social norms, in your daily life
◦ Describe how attitudes can be changed through cognitive dissonance and persuasion
◦ Explain how conformity, obedience, groupthink, social facilitation, social loafing, and altruism
relate to group behavior
◦ Explain prejudice, discrimination, and aggression
• Module 11: Personality
◦ Define personality and the contributions of Freud and neo-Freudians to personality theory
◦ Describe and differentiate between personality theories
◦ Explain the use and purpose of common personality tests
• Module 12: Emotion and Motivation
◦ Explain motivation, how it is influenced, and major theories about motivation
◦ Describe hunger and eating in relation to motivation, obesity, anorexia, and bulimia
◦ Describe sexual behavior and research about sexuality
◦ Explain theories of emotion and how we express and recognize emotion
• Module 13: Industrial-Organizational Psychology
◦ Describe the purpose of industrial-organizational psychology and examine its application to the
workforce
◦ Explain how industrial-organizational psychologists assess leadership and organization
Mental and Physical Health Domain
• Module 14: Psychological Disorders
◦ Define psychological disorders and explain how they are classified
◦ Describe the features and characteristic symptoms of anxiety disorders (generalized anxiety
disorder, panic disorder, phobias), obsessive-compulsive disorder and posttraumatic stress
disorder; differentiate these anxiety disorders from each other
◦ Describe the characteristic symptoms and risk factors of mood disorders, including major
depressive disorder and bipolar disorder
◦ Explain symptoms and potential causes of schizophrenic and dissociative disorders
◦ Define personality disorders and distinguish between the three clusters of personality disorders
◦ Explain common childhood disorders, including attention deficit/hyperactivity disorder and
autism spectrum disorder
• Module 15: Therapy and Treatment
◦ Describe the treatment of mental health disorders over time
◦ Identify and explain the basic characteristics of various types of therapy
◦ Explain and compare treatment modalities

• Module 16: Stress, Lifestyle, and Health
◦ Describe stress, its impact on the body, and identify common stressors
◦ Explain the negative physiological responses to stress
◦ Describe methods to cope with stress and explain ways to increase happiness
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Psychology is the scientific study of mind and behavior. (credit “background”: modification of work by Nattachai Noogure; credit
“top left”: modification of work by U.S. Navy; credit “top middle-left”: modification of work by Peter Shanks; credit “top middle-right”:
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right”: modification of work by Staffan Scherz; credit “bottom right”: modification of work by Czech Provincial Reconstruction
Team)
MODULE 1: PSYCHOLOGICAL
FOUNDATIONS
WHY IT MATTERS: PSYCHOLOGICAL
FOUNDATIONS
Clive Wearing is an accomplished musician who lost his ability to form new memories when he became sick at
the age of 46. While he can remember how to play the piano perfectly, he cannot remember what he ate for
breakfast just an hour ago (Sacks, 2007). James Wannerton experiences a taste sensation that is associated with
the sound of words. His former girlfriend’s name tastes like rhubarb (Mundasad, 2013). John Nash is a brilliant
mathematician and Nobel Prize winner. However, while he was a professor at MIT, he would tell people that the
New York Times contained coded messages from extraterrestrial beings that were intended for him. He also
began to hear voices and became suspicious of the people around him. Soon thereafter, Nash was diagnosed

with schizophrenia and admitted to a state-run mental institution (O’Connor & Robertson, 2002). Nash was the
subject of the 2001 movie A Beautiful Mind. Why did these people have these experiences? How does the human
brain work? And what is the connection between the brain’s internal processes and people’s external behaviors?
This course will introduce you to various ways that the field of psychology has explored these questions.
This module will introduce you to what psychology is and what psychologists do. You’ll learn the basic history of
the discipline and about the major domains and subdivisions that exist within modern psychology. Lastly, you’ll
consider what it means to study psychology and what career options are available for those who do.
AnswerAnswer
American Board of Forensic Psychology. (2014). Brochure. Retrieved from http://www.abfp.com/brochure.asp
American Psychological Association. (2014). Retrieved from www.apa.org
American Psychological Association. (2014). Graduate training and career possibilities in exercise and sport
psychology. Retrieved from http://www.apadivisions.org/division-47/about/resources/training.aspx?item=1
American Psychological Association. (2011). Psychology as a career. Retrieved from http://www.apa.org/
education/undergrad/psych-career.aspx
Ashliman, D. L. (2001). Cupid and Psyche. In Folktexts: A library of folktales, folklore, fairy tales, and mythology.
Retrieved from http://www.pitt.edu/~dash/cupid.html
Betancourt, H., & López, S. R. (1993). The study of culture, ethnicity, and race in American psychology. American
Psychologist, 48, 629–637.
Black, S. R., Spence, S. A., & Omari, S. R. (2004). Contributions of African Americans to the field of psychology.
Journal of Black Studies, 35, 40–64.
Bulfinch, T. (1855). The age of fable: Or, stories of gods and heroes. Boston, MA: Chase, Nichols and Hill.
Buss, D. M. (1989). Sex differences in human mate preferences: Evolutionary hypotheses tested in 37 cultures.
Behavioral and Brain Sciences, 12, 1–49.
Carlson, N. R. (2013). Physiology of Behavior (11th ed.). Boston, MA: Pearson.
Confer, J. C., Easton, J. A., Fleischman, D. S., Goetz, C. D., Lewis, D. M. G., Perilloux, C., & Buss, D. M. (2010).
Evolutionary psychology. Controversies, questions, prospects, and limitations. American Psychologist, 65,
100–126.
Crawford, M., & Marecek, J. (1989). Psychology reconstructs the female 1968–1988. Psychology of Women
Quarterly, 13, 147–165.
Danziger, K. (1980). The history of introspection reconsidered. Journal of the History of the Behavioral Sciences,
16, 241–262.
Darwin, C. (1871). Thedescent of man and selection in relation to sex. London: John Murray.
Darwin, C. (1872). The expression of the emotions in man and animals. London: John Murray.
DeAngelis, T. (2010). Fear not. gradPSYCH Magazine, 8, 38.
Department of Health and Human Services. (n.d.). Projected future growth of the older population. Retrieved from
http://www.aoa.gov/Aging_Statistics/future_growth/future_growth.aspx#age
Endler, J. A. (1986). Natural Selection in the Wild. Princeton, NJ: Princeton University Press.
Fogg, N. P., Harrington, P. E., Harrington, T. F., & Shatkin, L. (2012). College majors handbook with real career
paths and payoffs (3rd ed.). St. Paul, MN: JIST Publishing.
Franko, D. L., et al. (2012). Racial/ethnic differences in adults in randomized clinical trials of binge eating disorder.
Journal of Consulting and Clinical Psychology, 80, 186–195.

Friedman, H. (2008), Humanistic and positive psychology: The methodological and epistemological divide. The
Humanistic Psychologist, 36, 113–126.
Gordon, O. E. (1995). A brief history of psychology. Retrieved from http://www.psych.utah.edu/gordon/Classes/
Psy4905Docs/PsychHistory/index.html#maptop
Greek Myths & Greek Mythology. (2014). The myth of Psyche and Eros. Retrieved from http://www.greekmyths-
greekmythology.com/psyche-and-eros-myth/
Green, C. D. (2001). Classics in the history of psychology. Retrieved from http://psychclassics.yorku.ca/Krstic/
marulic.htm
Greengrass, M. (2004). 100 years of B.F. Skinner. Monitor on Psychology, 35, 80.
Halonen, J. S. (2011). White paper: Are there too many psychology majors? Prepared for the Staff of the State
University System of Florida Board of Governors. Retrieved from http://www.cogdop.org/page_attachments/0000/
0200/FLA_White_Paper_for_cogop_posting
Hock, R. R. (2009). Social psychology. Forty studies that changed psychology: Explorations into the history of
psychological research (pp. 308–317). Upper Saddle River, NJ: Pearson.
Hoffman, C. (2012). Careers in clinical, counseling, or school psychology; mental health counseling; clinical social
work; marriage & family therapy and related professions. Retrieved from http://www.indiana.edu/~psyugrad/
advising/docs/Careers%20in%20Mental%20Health%20Counseling
Jang, K. L., Livesly, W. J., & Vernon, P. A. (1996). Heritability of the Big Five personality dimensions and their
facets: A twin study. Journal of Personality, 64, 577–591.
Johnson, R., & Lubin, G. (2011). College exposed: What majors are most popular, highest paying and most likely
to get you a job. Business Insider.com. Retrieved from http://www.businessinsider.com/best-college-majors-
highest-income-most-employed-georgetwon-study-2011-6?op=1
Knekt, P. P., et al. (2008). Randomized trial on the effectiveness of long- and short-term psychodynamic
psychotherapy and solution-focused therapy on psychiatric symptoms during a 3-year follow-up. Psychological
Medicine: A Journal of Research In Psychiatry And The Allied Sciences, 38, 689–703.
Landers, R. N. (2011, June 14). Grad school: Should I get a PhD or Master’s in I/O psychology? [Web log post].
Retrieved from http://neoacademic.com/2011/06/14/grad-school-should-i-get-a-ph-d-or-masters-in-io-
psychology/#.UuKKLftOnGg
Macdonald, C. (2013). Health psychology center presents: What is health psychology? Retrieved from
http://healthpsychology.org/what-is-health-psychology/
McCrae, R. R. & Costa, P. T. (2008). Empirical and theoretical status of the five-factor model of personality traits.
In G. J. Boyle, G. Matthews, & D. H. Saklofske (Eds.), The Sage handbook of personality theory and assessment.
Vol. 1 Personality theories and models. London: Sage.
Michalski, D., Kohout, J., Wicherski, M., & Hart, B. (2011). 2009 Doctorate Employment Survey. APA Center for
Workforce Studies. Retrieved from http://www.apa.org/workforce/publications/09-doc-empl/index.aspx
Miller, G. A. (2003). The cognitive revolution: A historical perspective. Trends in Cognitive Sciences, 7, 141–144.
Munakata, Y., McClelland, J. L., Johnson, M. H., & Siegler, R. S. (1997). Rethinking infant knowledge: Toward an
adaptive process account of successes and failures in object permanence tasks. Psychological Review, 104,
689–713.
Mundasad, S. (2013). Word-taste synaesthesia: Tasting names, places, and Anne Boleyn. Retrieved from
http://www.bbc.co.uk/news/health-21060207
Munsey, C. (2009). More states forgo a postdoc requirement. Monitor on Psychology, 40, 10.

National Association of School Psychologists. (n.d.). Becoming a nationally certified school psychologist (NCSP).
Retrieved from http://www.nasponline.org/CERTIFICATION/becomeNCSP.aspx
Nicolas, S., & Ferrand, L. (1999). Wundt’s laboratory at Leipzig in 1891. History of Psychology, 2, 194–203.
Norcross, J. C. (n.d.) Clinical versus counseling psychology: What’s the diff? Available at
http://www.csun.edu/~hcpsy002/Clinical%20Versus%20Counseling%20Psychology
Norcross, J. C., & Castle, P. H. (2002). Appreciating the PsyD: The facts. Eye on Psi Chi, 7, 22–26.
O’Connor, J. J., & Robertson, E. F. (2002). John Forbes Nash. Retrieved from http://www-groups.dcs.st-
and.ac.uk/~history/Biographies/Nash.html
O’Hara, M. (n.d.). Historic review of humanistic psychology. Retrieved from http://www.ahpweb.org/
index.php?option=com_k2&view=item&layout=item&id=14&Itemid=24
Person, E. S. (1980). Sexuality as the mainstay of identity: Psychoanalytic perspectives. Signs, 5, 605–630.
Rantanen, J., Metsäpelto, R. L., Feldt, T., Pulkkinen, L., & Kokko, K. (2007). Long-term stability in the Big Five
personality traits in adulthood. Scandinavian Journal of Psychology, 48, 511–518.
Riggio, R. E. (2013). What is industrial/organizational psychology? Psychology Today. Retrieved from
http://www.psychologytoday.com/blog/cutting-edge-leadership/201303/what-is-industrialorganizational-
psychology
Sacks, O. (2007). A neurologists notebook: The abyss, music and amnesia. The New Yorker. Retrieved from
http://www.newyorker.com/reporting/2007/09/24/070924fa_fact_sacks?currentPage=all
Shedler, J. (2010). The efficacy of psychodynamic psychotherapy. American Psychologist, 65(2), 98–109.
Soldz, S., & Vaillant, G. E. (1999). The Big Five personality traits and the life course: A 45-year longitudinal study.
Journal of Research in Personality, 33, 208–232.
Thorne, B. M., & Henley, T. B. (2005). Connections in the history and systems of psychology (3rd ed.). Boston,
MA: Houghton Mifflin Company.
Tolman, E. C. (1938). The determiners of behavior at a choice point. Psychological Review, 45, 1–41.
U.S. Department of Education, National Center for Education Statistics. (2013). Digest of Education Statistics,
2012 (NCES 2014-015).
Weisstein, N. (1993). Psychology constructs the female: Or, the fantasy life of the male psychologist (with some
attention to the fantasies of his friends, the male biologist and the male anthropologist). Feminism and
Psychology, 3, 195–210.
Westen, D. (1998). The scientific legacy of Sigmund Freud, toward a psychodynamically informed psychological
science. Psychological Bulletin, 124, 333–371.
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THE HISTORY OF PSYCHOLOGY

What you’ll learn to do: describe the evolution of psychology and
the major pioneers in the field

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Antonio Canova’s sculpture depicts Eros and Psyche.
Plato, Aristotle, and other ancient Greek philosophers examined a wide range of topics relating to what we now consider
psychology.
Many cultures throughout history have speculated on the nature of the mind, heart, soul, spirit, and brain.
Philosophical interest in behavior and the mind dates back to the ancient civilizations of Egypt, Greece, China,
and India, but psychology as a discipline didn’t develop until the mid-1800s, when it evolved from the study of
philosophy and began in German and American labs. This section will teach you more about the major founding
psychologists and their contributions to the development of psychology.
LEARNING OBJECTIVESLEARNING OBJECTIVES
• Define Psychology
• Define structuralism and functionalism and the contributions of Wundt and James in the development
of psychology
• Describe Freud’s influence on psychology and his major theoretical contributions
• Describe the basic tenets of Gestalt psychology
What is Psychology?
In Greek mythology, Psyche was a mortal woman whose beauty was so great that it rivaled that of the goddess
Aphrodite. Aphrodite became so jealous of Psyche that she sent her son, Eros, to make Psyche fall in love with
the ugliest man in the world. However, Eros accidentally pricked himself with the tip of his arrow and fell madly in
love with Psyche himself. He took Psyche to his palace and showered her with gifts, yet she could never see his
face. While visiting Psyche, her sisters roused suspicion in Psyche about her mysterious lover, and eventually,
Psyche betrayed Eros’ wishes to remain unseen to her. Because of this betrayal, Eros abandoned Psyche. When
Psyche appealed to Aphrodite to reunite her with Eros, Aphrodite gave her a series of impossible tasks to
complete. Psyche managed to complete all of these trials; ultimately, her perseverance paid off as she was
reunited with Eros and was ultimately transformed into a goddess herself (Ashliman, 2001; Greek Myths & Greek
Mythology, 2014).
Psyche comes to represent the human soul’s triumph over
the misfortunes of life in the pursuit of true happiness
(Bulfinch, 1855); in fact, the Greek word psychepsyche means
soul, and it is often represented as a butterfly. The word
psychology was coined at a time when the concepts of
soul and mind were not as clearly distinguished (Green,
2001). The root –ologyology denotes scientific study of, and
psychology refers to the scientific study of the mind. Since
science studies only observable phenomena and the mind
is not directly observable, we expand this definition to the
scientific study of mind and behavior.
The scientific study of any aspect of the world uses the
scientific method to acquire knowledge. To apply the
scientific method, a researcher with a question about how
or why something happens will propose a tentative
explanation, called a hypothesis, to explain the
phenomenon. A hypothesis is not just any explanation; it
should fit into the context of a scientific theory. A scientific
theory is a broad explanation or group of explanations for
some aspect of the natural world that is consistently supported by evidence over time. A theory is the best
understanding that we have of that part of the natural world. Armed with the hypothesis, the researcher then
makes observations or, better still, carries out an experiment to test the validity of the hypothesis. That test and its
results are then published so that others can check the results or build on them. It is necessary that any
explanation in science be testable, which means that the phenomenon must be perceivable and measurable. For
example, that a bird sings because it is happy is not a testable hypothesis, since we have no way to measure the

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happiness of a bird. We must ask a different question, perhaps about the brain state of the bird, since this can be
measured. In general, science deals only with matter and energy, that is, those things that can be measured, and
it cannot arrive at knowledge about values and morality. This is one reason why our scientific understanding of
the mind is so limited, since thoughts, at least as we experience them, are neither matter nor energy. The
scientific method is also a form of empiricism. An empirical methodempirical method for acquiring knowledge is one based on
observation, including experimentation, rather than a method based only on forms of logical argument or previous
authorities.
It was not until the late 1800s that psychology became accepted as its own academic discipline. Before this time,
the workings of the mind were considered under the auspices of philosophy. Given that any behavior is, at its
roots, biological, some areas of psychology take on aspects of a natural science like biology. No biological
organism exists in isolation, and our behavior is influenced by our interactions with others. Therefore, psychology
is also a social science.
Psychology is a relatively young science with its experimental roots in the 19th century, compared, for example, to
human physiology, which dates much earlier. As mentioned, anyone interested in exploring issues related to the
mind generally did so in a philosophical context prior to the 19th century. Two men, working in the 19th century,
are generally credited as being the founders of psychology as a science and academic discipline that was distinct
from philosophy. Their names were Wilhelm Wundt and William James.
Wundt and Structuralism
Wilhelm Wundt (1832–1920) was a German scientist who was the first person to be referred to as a psychologist.
His famous book entitled Principles of Physiological Psychology was published in 1873. Wundt viewed
psychology as a scientific study of conscious experience, and he believed that the goal of psychology was to
identify components of consciousness and how those components combined to result in our conscious
experience. Wundt used introspection (he called it “internal perception”), a process by which someone examines
their own conscious experience as objectively as possible, making the human mind like any other aspect of
nature that a scientist observed. Wundt’s version of introspection used only very specific experimental conditions
in which an external stimulus was designed to produce a scientifically observable (repeatable) experience of the
mind (Danziger, 1980). The first stringent requirement was the use of “trained” or practiced observers, who could
immediately observe and report a reaction. The second requirement was the use of repeatable stimuli that always
produced the same experience in the subject and allowed the subject to expect and thus be fully attentive to the
inner reaction. These experimental requirements were put in place to eliminate “interpretation” in the reporting of
internal experiences and to counter the argument that there is no way to know that an individual is observing their
mind or consciousness accurately, since it cannot be seen by any other person. This attempt to understand the
structure or characteristics of the mind was known as structuralismstructuralism. Wundt established his psychology laboratory
at the University at Leipzig in 1879. In this laboratory, Wundt and his students conducted experiments on, for
example, reaction times. A subject, sometimes in a room isolated from the scientist, would receive a stimulus
such as a light, image, or sound. The subject’s reaction to the stimulus would be to push a button, and an

structuralism. Like Wundt, James believed that introspection could serve as one means by which someone might
study mental activities, but James also relied on more objective measures, including the use of various recording
devices, and examinations of concrete products of mental activities and of anatomy and physiology (Gordon,
1995).

Figure 1. (a) Sigmund Freud was a highly influential figure
in the history of psychology. (b) One of his many books, A
General Introduction to Psychoanalysis, shared his ideas
about psychoanalytical therapy; it was published in 1922
Image of a clip-art iceberg, with large portions of
its superego and ego under the surface of the
water, with the id at the bottom of the iceberg. The
exposed portion is conscious experience.
Figure 2. Freud’s theory of the unconscious Freud
believed that we are only aware of a small amount of our
mind’s activity, and that most of it remains hidden from us
in our unconscious. The information in our unconscious
affects our behavior, although we are unaware of it.
Psychoanalytic Theory
Perhaps one of the most influential and well-known figures
in psychology’s history was Sigmund Freud. Freud
(1856–1939) was an Austrian neurologist who was
fascinated by patients suffering from “hysteria” and
neurosis. Hysteria was an ancient diagnosis for disorders,
primarily of women with a wide variety of symptoms,
including physical symptoms and emotional disturbances,
none of which had an apparent physical cause. Freud
theorized that many of his patients’ problems arose from
the unconscious mind. In Freud’s view, the unconscious
mind was a repository of feelings and urges of which we
have no awareness. Gaining access to the unconscious,
then, was crucial to the successful resolution of the
patient’s problems. According to Freud, the unconscious
mind could be accessed through dream analysis, by
examinations of the first words that came to people’s minds,
and through seemingly innocent slips of the tongue.
Psychoanalytic theoryPsychoanalytic theory focuses on the role of a person’s
unconscious, as well as early childhood experiences, and
this particular perspective dominated clinical psychology for several decades (Thorne & Henley, 2005).
The Id, Ego, and Superego
Freud’s structural model of personality divides the personality into three parts—the id, the ego, and the superego.
The id is the unconscious part that is the cauldron of raw drives, such as for sex or aggression. The ego, which
has conscious and unconscious elements, is the rational and reasonable part of personality. Its role is to maintain
contact with the outside world to keep the individual in touch with society, and to do this it mediates between the
conflicting tendencies of the id and the superego. The superego is a person’s conscience, which develops early in
life and is learned from parents, teachers, and others. Like the ego, the superego has conscious and unconscious
elements. When all three parts of the personality are in dynamic equilibrium, the individual is thought to be
mentally healthy. However, if the ego is unable to mediate between the id and the superego, an imbalance is
believed to occur in the form of psychological distress.
Psychosexual Theory of Development
Freud’s theories also placed a great deal of emphasis on
sexual development. Freud believed that each of us must
pass through a series of stages during childhood, and that if
we lack proper nurturing during a particular stage, we may
become stuck or fixated in that stage. Freud’s psychosexual
model of development includes five stages: oral, anal,
phallic, latency, and genital. According to Freud, children’s
pleasure-seeking urges are focused on a different area of the body, called an erogenous zone, at each of these
five stages. Psychologists today dispute that Freud’s psychosexual stages provide a legitimate explanation for
how personality develops, but what we can take away from Freud’s theory is that personality is shaped, in some
part, by experiences we have in childhood.
Freud’s ideas were influential, and you will learn more about them when you study lifespan development,
personality, and therapy. For instance, many therapists believe strongly in the unconscious and the impact of
early childhood experiences on the rest of a person’s life. The method of psychoanalysis, which involves the
patient talking about their experiences and selves, while not invented by Freud, was certainly popularized by him
and is still used today. Many of Freud’s other ideas, however, are controversial.

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Figure 3. When you look at this image, you may see a
duck or a rabbit. The sensory information remains the
same, but your perception can vary dramatically.
Figure 4. The “invisible” triangle you see here is an
example of gestalt perception.
TRY ITTRY IT
Gestalt Psychology (Wertheimer, Koffka, and Köhler)
Max Wertheimer (1880–1943), Kurt Koffka (1886–1941),
and Wolfgang Köhler (1887–1967) were three German
psychologists who immigrated to the United States in the
early 20th century to escape Nazi Germany. These men are
credited with introducing psychologists in the United States
to various Gestalt principles. The word Gestalt roughly
translates to “whole;” a major emphasis of Gestalt
psychology deals with the fact that although a sensory
experience can be broken down into individual parts, how
those parts relate to each other as a whole is often what the
individual responds to in perception. For example, a song
may be made up of individual notes played by different
instruments, but the real nature of the song is perceived in
the combinations of these notes as they form the melody,
rhythm, and harmony. In many ways, this particular
perspective would have directly contradicted Wundt’s ideas
of structuralism (Thorne & Henley, 2005).
Unfortunately, in moving to the United States, these men
were forced to abandon much of their work and were
unable to continue to conduct research on a large scale.
These factors along with the rise of behaviorism (described
next) in the United States prevented principles of Gestalt
psychology from being as influential in the United States as
they had been in their native Germany (Thorne & Henley,
2005). Despite these issues, several Gestalt principles are
still very influential today. Considering the human individual
as a whole rather than as a sum of individually measured
parts became an important foundation in humanistic theory
late in the century. The ideas of Gestalt have continued to
influence research on sensation and perception.
Structuralism, Freud, and the Gestalt psychologists were all
concerned in one way or another with describing and
understanding inner experience. But other researchers had
concerns that inner experience could be a legitimate
subject of scientific inquiry and chose instead to exclusively
study behavior, the objectively observable outcome of mental processes.

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GLOSSARYGLOSSARY
empirical method:empirical method: method for acquiring knowledge based on observation, including experimentation, rather
than a method based only on forms of logical argument or previous authorities
functionalism:functionalism: focused on how mental activities helped an organism adapt to its environment
-ology:-ology: suffix that denotes “scientific study of”
psyche:psyche: Greek word for soul
psychoanalytic theory:psychoanalytic theory: focus on the role of the unconscious in affecting conscious behavior
psychology:psychology: scientific study of the mind and behavior
structuralism:structuralism: understanding the conscious experience through introspection
THINK IT OVERTHINK IT OVER
Freud is probably one of the most well-known historical figures in psychology. Where have you encountered
references to Freud or his ideas about the role that the unconscious mind plays in determining conscious
behavior?
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THE HISTORY OF PSYCHOLOGY CONTINUED
LEARNING OBJECTIVESLEARNING OBJECTIVES
• Define behaviorism and the contributions of Pavlov, Watson, and Skinner to psychology
• Explain the basic tenets of humanism and Maslow’s contribution to psychology
• Describe the basics of cognitive psychology and how the cognitive revolution shifted psychology’s
focus back to the mind
• Summarize the history of psychology, focusing on the major schools of thought

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Figure 1. John B. Watson is known as the father of
behaviorism within psychology.
Behavioral Psychology
Early work in the field of behavior was conducted by the Russian physiologist Ivan Pavlov (1849–1936). Pavlov
studied a form of learning behavior called a conditioned reflex, in which an animal or human produced a reflex
(unconscious) response to a stimulus and, over time, was conditioned to produce the response to a different
stimulus that the experimenter associated with the original stimulus. The reflex Pavlov worked with was salivation
in response to the presence of food. The salivation reflex could be elicited using a second stimulus, such as a
specific sound, that was presented in association with the initial food stimulus several times. Once the response
to the second stimulus was “learned,” the food stimulus could be omitted. Pavlov’s “classical conditioning” is only
one form of learning behavior studied by behaviorists.
John B. Watson (1878–1958) was an influential American
psychologist whose most famous work occurred during the
early 20th century at Johns Hopkins University. While
Wundt and James were concerned with understanding
conscious experience, Watson thought that the study of
consciousness was flawed. Because he believed that
objective analysis of the mind was impossible, Watson
preferred to focus directly on observable behavior and try to
bring that behavior under control. Watson was a major
proponent of shifting the focus of psychology from the mind
to behavior, and this approach of observing and controlling
behavior came to be known as behaviorismbehaviorism. A major object
of study by behaviorists was learned behavior and its
interaction with inborn qualities of the organism.
Behaviorism commonly used animals in experiments under
the assumption that what was learned using animal models
could, to some degree, be applied to human behavior.
Indeed, Tolman (1938) stated, “I believe that everything
important in psychology (except … such matters as involve society and words) can be investigated in essence
through the continued experimental and theoretical analysis of the determiners of rat behavior at a choice-point in
a maze.”
Behaviorism dominated experimental psychology for several decades, and its influence can still be felt today
(Thorne & Henley, 2005). Behaviorism is largely responsible for establishing psychology as a scientific discipline
through its objective methods and especially experimentation. In addition, it is used in behavioral and cognitive-
behavioral therapy. Behavior modification is commonly used in classroom settings. Behaviorism has also led to
research on environmental influences on human behavior.
B. F. Skinner (1904–1990) was an American psychologist. Like Watson, Skinner was a behaviorist, and he
concentrated on how behavior was affected by its consequences. Therefore, Skinner spoke of reinforcement and
punishment as major factors in driving behavior. As a part of his research, Skinner developed a chamber that
allowed the careful study of the principles of modifying behavior through reinforcement and punishment. This
device, known as an operant conditioning chamber (or more familiarly, a Skinner box), has remained a crucial
resource for researchers studying behavior (Thorne & Henley, 2005).

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Figure 2. (a) B. F. Skinner is famous for his research on operant conditioning. (b) Modified versions of the operant conditioning
chamber, or Skinner box, are still widely used in research settings today. (credit a: modification of work by “Silly rabbit”/Wikimedia
Commons)
The Skinner box is a chamber that isolates the subject from the external environment and has a behavior
indicator such as a lever or a button. When the animal pushes the button or lever, the box is able to deliver a
positive reinforcement of the behavior (such as food) or a punishment (such as a noise) or a token conditioner
(such as a light) that is correlated with either the positive reinforcement or punishment.
Skinner’s focus on positive and negative reinforcement of learned behaviors had a lasting influence in psychology
that has waned somewhat since the growth of research in cognitive psychology. Despite this, conditioned learning
is still used in human behavioral modification. Skinner’s two widely read and controversial popular science books
about the value of operant conditioning for creating happier lives remain as thought-provoking arguments for his
approach (Greengrass, 2004).
During the early 20th century, American psychology was dominated by behaviorism and psychoanalysis.
However, some psychologists were uncomfortable with what they viewed as limited perspectives being so
influential to the field. They objected to the pessimism and determinism (all actions driven by the unconscious) of
Freud. They also disliked the reductionism, or simplifying nature, of behaviorism. Behaviorism is also deterministic
at its core, because it sees human behavior as entirely determined by a combination of genetics and environment.
Some psychologists began to form their own ideas that emphasized personal control, intentionality, and a true
predisposition for “good” as important for our self-concept and our behavior. Thus, humanism emerged.

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Figure 3.
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Maslow, Rogers, and Humanism
HumanismHumanism is a perspective within psychology that emphasizes the potential for good that is innate to all humans.
Two of the most well-known proponents of humanistic psychology are Abraham Maslow and Carl Rogers
(O’Hara, n.d.). Abraham Maslow (1908–1970) was an American psychologist who is best known for proposing a
hierarchy of human needs in motivating behavior. Although this concept will be discussed in more detail in a later
section, a brief overview will be provided here.
Maslow asserted that so long as basic needs necessary for survival were met (e.g., food, water, shelter), higher-
level needs (e.g., social needs) would begin to motivate behavior. According to Maslow, the highest-level needs
relate to self-actualization, a process by which we achieve our full potential. Obviously, the focus on the positive
aspects of human nature that are characteristic of the humanistic perspective is evident (Thorne & Henley, 2005).
Humanistic psychologists rejected, on principle, the research approach based on reductionist experimentation in
the tradition of the physical and biological sciences, because it missed the “whole” human being. Beginning with
Maslow and Rogers, there was an insistence on a humanistic research program. This program has been largely
qualitative (not measurement-based), but there exist a number of quantitative research strains within humanistic
psychology, including research on happiness, self-concept, meditation, and the outcomes of humanistic
psychotherapy (Friedman, 2008).
Carl Rogers (1902–1987) was also an American
psychologist who, like Maslow, emphasized the potential for
good that exists within all people. Rogers used a
therapeutic technique known as client-centered therapy in
helping his clients deal with problematic issues that resulted
in their seeking psychotherapy. Unlike a psychoanalytic
approach in which the therapist plays an important role in
interpreting what conscious behavior reveals about the
unconscious mind, client-centered therapy involves the
patient taking a lead role in the therapy session. Rogers
believed that a therapist needed to display three features to
maximize the effectiveness of this particular approach:
unconditional positive regard, genuineness, and empathy.
Unconditional positive regard refers to the fact that the
therapist accepts their client for who they are, no matter
what he or she might say. Provided these factors, Rogers
believed that people were more than capable of dealing
with and working through their own issues (Thorne &
Henley, 2005).
Humanism has been influential to psychology as a whole.
Both Maslow and Rogers are well-known names among
students of psychology (you will read more about both men
later in this text), and their ideas have influenced many
scholars. Furthermore, Rogers’ client-centered approach to
therapy is still commonly used in psychotherapeutic settings today (O’hara, n.d.).

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The Cognitive Revolution
Behaviorism’s emphasis on objectivity and focus on external behavior had pulled psychologists’ attention away
from the mind for a prolonged period of time. The early work of the humanistic psychologists redirected attention
to the individual human as a whole, and as a conscious and self-aware being. By the 1950s, new disciplinary
perspectives in linguistics, neuroscience, and computer science were emerging, and these areas revived interest
in the mind as a focus of scientific inquiry. This particular perspective has come to be known as the cognitive
revolution (Miller, 2003). By 1967, Ulric Neisser published the first textbook entitled Cognitive Psychology, which
served as a core text in cognitive psychology courses around the country (Thorne & Henley, 2005).Although no
one person is entirely responsible for starting the cognitive revolution, Noam Chomsky was very influential in the
early days of this movement. Chomsky (1928–), an American linguist, was dissatisfied with the influence that
behaviorism had had on psychology. He believed that psychology’s focus on behavior was short-sighted and that
the field had to re-incorporate mental functioning into its purview if it were to offer any meaningful contributions to
understanding behavior (Miller, 2003).

Noam Chomsky was very influential in beginning the
cognitive revolution. In 2010, this mural honoring him was
put up in Philadelphia, Pennsylvania. (credit: Robert
Moran)
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European psychology had never really been as influenced
by behaviorism as had American psychology; and thus, the
cognitive revolution helped reestablish lines of
communication between European psychologists and their
American counterparts. Furthermore, psychologists began
to cooperate with scientists in other fields, like
anthropology, linguistics, computer science, and
neuroscience, among others. This interdisciplinary
approach often was referred to as the cognitive sciences,
and the influence and prominence of this particular
perspective resonates in modern-day psychology (Miller,
2003).
Cognitive Psychology
Cognitive psychology is radically different from previous
psychological approaches in that it is characterized by both
of the following:
1. It accepts the use of the scientific method and
generally rejects introspection as a valid method of
investigation, unlike phenomenological methods such as Freudian psychoanalysis.
2. It explicitly acknowledges the existence of internal mental states (such as belief, desire, and motivation),
unlike behaviorist psychology.
Cognitive theory contends that solutions to problems take the form of algorithms, heuristics, or insights. Major
areas of research in cognitive psychology include perception, memory, categorization, knowledge representation,
numerical cognition, language, and thinking.
Multicultural Psychology
Culture has important impacts on individuals and social psychology, yet the effects of culture on psychology are
under-studied. There is a risk that psychological theories and data derived from white, American settings could be
assumed to apply to individuals and social groups from other cultures and this is unlikely to be true (Betancourt &
López, 1993). One weakness in the field of cross-cultural psychology is that in looking for differences in
psychological attributes across cultures, there remains a need to go beyond simple descriptive statistics
(Betancourt & López, 1993). In this sense, it has remained a descriptive science, rather than one seeking to
determine cause and effect. For example, a study of characteristics of individuals seeking treatment for a binge
eating disorder in Hispanic American, African American, and Caucasian American individuals found significant
differences between groups (Franko et al., 2012). The study concluded that results from studying any one of the
groups could not be extended to the other groups, and yet potential causes of the differences were not measured.
This history of multicultural psychology in the United States is a long one. The role of African American
psychologists in researching the cultural differences between African American individual and social psychology is
but one example. In 1920, Cecil Sumner was the first African American to receive a PhD in psychology in the
United States. Sumner established a psychology degree program at Howard University, leading to the education
of a new generation of African American psychologists (Black, Spence, and Omari, 2004). Much of the work of
early African American psychologists (and a general focus of much work in first half of the 20th century in
psychology in the United States) was dedicated to testing and intelligence testing in particular (Black et al., 2004).

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Learn more about the history of psychology through the following PsychSim Tutorial. The tutorial is only
intended for practice. Please disregard the final screen that requests you submit answers to your instructor.
• Psychology’s Timeline
That emphasis has continued, particularly because of the importance of testing in determining opportunities for
children, but other areas of exploration in African-American psychology research include learning style, sense of
community and belonging, and spiritualism (Black et al., 2004).
The American Psychological Association has several ethnically based organizations for professional
psychologists that facilitate interactions among members. Since psychologists belonging to specific ethnic groups
or cultures have the most interest in studying the psychology of their communities, these organizations provide an
opportunity for the growth of research on the impact of culture on individual and social psychology.
Summary of the History of Psychology
Before the time of Wundt and James, questions about the mind were considered by philosophers. However, both
Wundt and James helped create psychology as a distinct scientific discipline. Wundt was a structuralist, which
meant he believed that our cognitive experience was best understood by breaking that experience into its
component parts. He thought this was best accomplished by introspection.
William James was the first American psychologist, and he was a proponent of functionalism. This particular
perspective focused on how mental activities served as adaptive responses to an organism’s environment. Like
Wundt, James also relied on introspection; however, his research approach also incorporated more objective
measures as well.
Sigmund Freud believed that understanding the unconscious mind was absolutely critical to understand
conscious behavior. This was especially true for individuals that he saw who suffered from various hysterias and
neuroses. Freud relied on dream analysis, slips of the tongue, and free association as means to access the
unconscious. Psychoanalytic theory remained a dominant force in clinical psychology for several decades.
Gestalt psychology was very influential in Europe. Gestalt psychology takes a holistic view of an individual and his
experiences. As the Nazis came to power in Germany, Wertheimer, Koffka, and Köhler immigrated to the United
States. Although they left their laboratories and their research behind, they did introduce America to Gestalt ideas.
Some of the principles of Gestalt psychology are still very influential in the study of sensation and perception.
One of the most influential schools of thought within psychology’s history was behaviorism. Behaviorism focused
on making psychology an objective science by studying overt behavior and deemphasizing the importance of
unobservable mental processes. John Watson is often considered the father of behaviorism, and B. F. Skinner’s
contributions to our understanding of principles of operant conditioning cannot be underestimated.
As behaviorism and psychoanalytic theory took hold of so many aspects of psychology, some began to become
dissatisfied with psychology’s picture of human nature. Thus, a humanistic movement within psychology began to
take hold. Humanism focuses on the potential of all people for good. Both Maslow and Rogers were influential in
shaping humanistic psychology.
During the 1950s, the landscape of psychology began to change. A science of behavior began to shift back to its
roots of focus on mental processes. The emergence of neuroscience and computer science aided this transition.
Ultimately, the cognitive revolution took hold, and people came to realize that cognition was crucial to a true
appreciation and understanding of behavior.

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GLOSSARYGLOSSARY
behaviorism:behaviorism: focus on observing and controlling behavior
humanism:humanism: perspective within psychology that emphasizes the potential for good that is innate to all humans
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Early Schools of Psychology: Still Active and Advanced Beyond Early Ideas
School ofSchool of
PsychologyPsychology
DescriptionDescription
EarliestEarliest
PeriodPeriod
HistoricallyHistorically
Important PeopleImportant People
Psychodynamic
Psychology
Focuses on the role of the unconscious and
childhood experiences in affecting conscious
behavior.
Very late
19th to
Early 20th
Century
Sigmund Freud,
Erik Erikson
Behaviorism
Focuses on observing and controlling behavior
through what is observable. Puts an
emphasis on learning and conditioning.
Early 20th
Century
Ivan Pavlov, John
B. Watson, B. F.
Skinner
Cognitive Psychology
Focuses not just on behavior, but on on mental
processes and internal mental states.
1920s
Ulric Neisser,Noam
Chomsky, Jean
Piaget, Lev
Vygotsky
Humanistic
Psychology
Emphasizes the potential for good that is innate
to all humans and rejects that psychology
should focus on problems and disorders.
1950s
Abraham Maslow,
Carl Rogers

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DOMAINS IN PSYCHOLOGY
What you’ll learn to do: identify the various approaches, fields, and
subfields of psychology along with their major concepts and
important figures
This section will provide an overview of the major domains of psychology today, as well as some additional sub-
fields and content areas. This is not meant to be an exhaustive listing, but it will provide insight into the major
areas of research and practice of modern-day psychologists. You’ll come to see that while psychology is defined
as the study of the mind and behavior, there are many different types of psychologists who emphasize and apply
psychological principles in various ways.
For example, imagine that a woman is diagnosed with depression. What is the cause of the depression? Is it her
biology or chemical imbalances in her brain? Evolutionary predispositions? Perhaps it is caused by experiences in
her past, or something else that triggered a downward spiral of emotions? Or maybe it is caused by social factors,
or cultural expectations? All of these things could, in fact, play a role in her depression. In this section, you’ll see

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Please visit this website to learn about the divisions within the APA. Student resources are also provided by the
APA.
how psychologists analyze behavior from a variety of perspectives and better understand the breadth of
psychology.
LEARNING OBJECTIVESLEARNING OBJECTIVES
• List and define the five major domains, or pillars, of contemporary psychology
• Describe the basic interests and applications of biopsychology and evolutionary psychology
• Describe the basic interests and applications of cognitive psychology
• Describe the basic interests and applications of developmental psychology
• Describe the basic interests and applications of social psychology and personality psychology
• Describe the basic interests and applications of abnormal, clinical, and health psychology
• Define industrial-organizational psychology, sport and exercise psychology, and forensic psychology
Introduction to Contemporary Psychology
Contemporary psychology is a diverse field that is influenced by all of the historical perspectives described in the
previous section of reading. Reflective of the discipline’s diversity is the diversity seen within the AmericanAmerican
Psychological AssociationPsychological Association (APA). The APA is a professional organization representing psychologists in the United
States. The APA is the largest organization of psychologists in the world, and its mission is to advance and
disseminate psychological knowledge for the betterment of people. There are 56 divisions within the APA,
representing a wide variety of specialties that range from Societies for the Psychology of Religion and Spirituality
to Exercise and Sport Psychology to Behavioral Neuroscience and Comparative Psychology. Reflecting the
diversity of the field of psychology itself, members, affiliate members, and associate members span the spectrum
from students to doctoral-level psychologists, and come from a variety of places including educational settings,
criminal justice, hospitals, the armed forces, and industry (American Psychological Association, 2014).
Psychologists agree that there is no one right way to study the way people think or behave. There are, however,
various schools of thought that evolved throughout the development of psychology that continue to shape the way
we investigate human behavior. For example, some psychologists might attribute a certain behavior to biological
factors such as genetics while another psychologist might consider early childhood experiences to be a more
likely explanation for the behavior. Many expert psychologists focus their entire careers on just one facet of
psychology, such as developmental psychology or cognitive psychology, or even more specifically, newborn
intelligence or language processing.
While the field of study is large and vast, this text aims to introduce you to the main topics with psychology. You’ll
get exposure to the various branches and sub-fields within the discipline and come to understand how they are all
interconnected and essential in understanding behavior and mental processes. The five main psychological
pillars, or domains, as we will refer to them, are:
1. Domain 1: Biological (includes neuroscience, consciousness, and sensation)
2. Domain 2: Cognitive (includes the study of perception, cognition, memory, and intelligence)
3. Domain 3: Development (includes learning and conditioning, lifespan development, and language)
4. Domain 4: Social and Personality (includes the study of personality, emotion, motivation, gender, and
culture)
5. Domain 5: Mental and Physical Health (includes abnormal psychology, therapy, and health psychology)

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HELPFUL HINTSHELPFUL HINTS
A neat way to remember the major perspectives in psychology is to think about your hand and associate each
finger with a psychological approach:
• ThumbThumb: your thumb can move around in PSYCHO ways—it’s so versatile! This is the psychodynamicpsychodynamic
perspective.
• Index FingerIndex Finger: Tap your finger to the temple of your head as if you were THINKING about something.
This is the cognitivecognitive perspective.
• Middle Finger:Middle Finger: If you stuck up your middle finger to flip someone off, that would be bad BEHAVIOR in
many cultures. This is the behavioralbehavioral perspective.
• Ring Finger:Ring Finger: This is where you would wear a wedding band. A humanistichumanistic psychologist would
emphasize everyone’s potential for marriage, or more likely, for self-actualization.
• Pinky Finger:Pinky Finger: This little finger was born this way—short. Thank your BIOLOGY for that. BiologicalBiological
perspective.
• Palm of hand:Palm of hand: Socio-culturalSocio-cultural. In many cultures, giving a high-five is an acceptable greeting.
Figure 1. The five pillars, or domains, of psychology. Image adapted from Gurung, R. A., Hackathorn, J., Enns, C., Frantz, S.,
Cacioppo, J. T., Loop, T., & Freeman, J. E. (2016) article “Strengthening introductory psychology: A new model for teaching the
introductory course” from American Psychologist.
These five domains cover the main viewpoints, or perspectives, of psychology. These perspectives emphasize
certain assumptions about behavior and provide a framework for psychologists in conducting research and
analyzing behavior. They include some you have already read about, including Freud’s psychodynamic
perspective, behaviorism, humanism, and the cognitive approach. Other perspectives include the biological
perspective, evolutionary, and socio-cultural perspectives.

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The Biological Domain
Biopsychology—also known as biological psychology or psychobiology—is the application of the principles of
biology to the study of mental processes and behavior. As the name suggests, biopsychologybiopsychology explores how our
biology influences our behavior. While biological psychology is a broad field, many biological psychologists want
to understand how the structure and function of the nervous system is related to behavior. The fields of behavioral
neuroscience, cognitive neuroscience, and neuropsychology are all subfields of biological psychology.
Figure 2. Different brain-imaging techniques provide scientists with insight into different aspects of how the human brain functions.

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The research interests of biological psychologists span a number of domains, including but not limited to, sensory
and motor systems, sleep, drug use and abuse, ingestive behavior, reproductive behavior, neurodevelopment,
plasticity of the nervous system, and biological correlates of psychological disorders. Given the broad areas of
interest falling under the purview of biological psychology, it will probably come as no surprise that individuals
from all sorts of backgrounds are involved in this research, including biologists, medical professionals,
physiologists, and chemists. This interdisciplinary approach is often referred to as neuroscience, of which
biological psychology is a component (Carlson, 2013).
Evolutionary Psychology
While biopsychology typically focuses on the immediate causes of behavior based in the physiology of a human
or other animal, evolutionary psychology seeks to study the ultimate biological causes of behavior. To the extent
that a behavior is impacted by genetics, a behavior, like any anatomical characteristic of a human or animal, will
demonstrate adaption to its surroundings. These surroundings include the physical environment and, since
interactions between organisms can be important to survival and reproduction, the social environment. The study
of behavior in the context of evolution has its origins with Charles Darwin, the co-discoverer of the theory of
evolution by natural selection. Darwin was well aware that behaviors should be adaptive and wrote books titled,
The Descent of Man (1871) and The Expression of the Emotions in Man and Animals (1872), to explore this field.
Evolutionary psychology, and specifically, the evolutionary psychology of humans, has enjoyed a resurgence in
recent decades. To be subject to evolution by natural selection, a behavior must have a significant genetic cause.
In general, we expect all human cultures to express a behavior if it is caused genetically, since the genetic
differences among human groups are small. The approach taken by most evolutionary psychologists is to predict
the outcome of a behavior in a particular situation based on evolutionary theory and then to make observations, or
conduct experiments, to determine whether the results match the theory. It is important to recognize that these
types of studies are not strong evidence that a behavior is adaptive, since they lack information that the behavior
is in some part genetic and not entirely cultural (Endler, 1986). Demonstrating that a trait, especially in humans, is
naturally selected is extraordinarily difficult; perhaps for this reason, some evolutionary psychologists are content
to assume the behaviors they study have genetic determinants (Confer et al., 2010).
One other drawback of evolutionary psychology is that the traits that we possess now evolved under
environmental and social conditions far back in human history, and we have a poor understanding of what these
conditions were. This makes predictions about what is adaptive for a behavior difficult. Behavioral traits need not
be adaptive under current conditions, only under the conditions of the past when they evolved, about which we
can only hypothesize.
There are many areas of human behavior for which evolution can make predictions. Examples include memory,
mate choice, relationships between kin, friendship and cooperation, parenting, social organization, and status
(Confer et al., 2010).
Evolutionary psychologists have had success in finding experimental correspondence between observations and
expectations. In one example, in a study of mate preference differences between men and women that spanned
37 cultures, Buss (1989) found that women valued earning potential factors greater than men, and men valued
potential reproductive factors (youth and attractiveness) greater than women in their prospective mates. In
general, the predictions were in line with the predictions of evolution, although there were deviations in some
cultures.
Sensation and Perception
Scientists interested in both physiological aspects of sensory systems as well as in the psychological experience
of sensory information work within the area of sensation and perception. As such, sensation and perception
research is also quite interdisciplinary. Imagine walking between buildings as you move from one class to
another. You are inundated with sights, sounds, touch sensations, and smells. You also experience the
temperature of the air around you and maintain your balance as you make your way. These are all factors of
interest to someone working in the domain of sensation and perception.

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The Cognitive Domain
As mentioned earlier, the cognitive revolution created an impetus for psychologists to focus their attention on
better understanding the mind and mental processes that underlie behavior. Thus, cognitive psychologycognitive psychology is the
area of psychology that focuses on studying cognitions, or thoughts, and their relationship to our experiences and
our actions. Like biological psychology, cognitive psychology is broad in its scope and often involves
collaborations among people from a diverse range of disciplinary backgrounds. This has led some to coin the
term cognitive science to describe the interdisciplinary nature of this area of research (Miller, 2003).
Cognitive psychologists have research interests that span a spectrum of topics, ranging from attention to problem
solving to language to memory. The approaches used in studying these topics are equally diverse. The bulk of
content coverage on cognitive psychology will be covered in the modules in this text on thinking, intelligence, and
memory. But given its diversity, various concepts related to cognitive psychology will be covered in other sections
such as lifespan development, social psychology, and therapy.
The Developmental Domain
Developmental psychologyDevelopmental psychology is the scientific study of development across a lifespan. Developmental psychologists
are interested in processes related to physical maturation. However, their focus is not limited to the physical
changes associated with aging, as they also focus on changes in cognitive skills, moral reasoning, social
behavior, and other psychological attributes. Early developmental psychologists focused primarily on changes
that occurred through reaching adulthood, providing enormous insight into the differences in physical, cognitive,
and social capacities that exist between very young children and adults. For instance, research by Jean
Piaget demonstrated that very young children do not demonstrate object permanence. Object permanence refers
to the understanding that physical things continue to exist, even if they are hidden from us. If you were to show an
adult a toy, and then hide it behind a curtain, the adult knows that the toy still exists. However, very young infants
act as if a hidden object no longer exists. The age at which object permanence is achieved is somewhat
controversial (Munakata, McClelland, Johnson, and Siegler, 1997).

Figure 3. Piaget is best known for his stage theory of
cognitive development.
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While Piaget was focused on cognitive changes during
infancy and childhood as we move to adulthood, there is an
increasing interest in extending research into the changes
that occur much later in life. This may be reflective of
changing population demographics of developed nations as
a whole. As more and more people live longer lives, the
number of people of advanced age will continue to
increase. Indeed, it is estimated that there were just over 40
million people aged 65 or older living in the United States in
2010. However, by 2020, this number is expected to
increase to about 55 million. By the year 2050, it is
estimated that nearly 90 million people in this country will
be 65 or older (Department of Health and Human Services,
n.d.).
Behavioral Psychology
Another critical field of study under the development
domain is that of learning and behaviorism, which you
read about already. The primary developments in learning
and conditioning came from the work of Ivan Pavlov, John
B. Watson, Edward Lee Thorndike, and B. F. Skinner.
Contemporary behaviorists apply learning techniques in the
form of behavior modification for a variety of mental
problems. Learning is seen as behavior change molded by
experience; it is accomplished largely through either
classical or operant conditioning.
The Social and Personality
Psychology Domain
Social psychology is the scientific study of how people’s thoughts, feelings, and behaviors are influenced by the
actual, imagined, or implied presence of others. This domain of psychology is concerned with the way such
feelings, thoughts, beliefs, intentions, and goals are constructed, and how these psychological factors, in turn,
influence our interactions with others.
Social psychology typically explains human behavior as a result of the interaction of mental states and immediate
social situations. Social psychologists, therefore, examine the factors that lead us to behave in a given way in the

Figure 4. Stanley Milgram’s research demonstrated just
how far people will go in obeying orders from an authority
figure. This advertisement was used to recruit subjects for
his research.
presence of others, as well as the conditions under which certain behaviors, actions, and feelings occur. They
focus on how people construe or interpret situations and how these interpretations influence their thoughts,
feelings, and behaviors (Ross & Nisbett, 1991). Thus, social psychology studies individuals in a social context and
how situational variables interact to influence behavior.
Some social psychologists study large-scale sociocultural forces within cultures and societies that affect the
thoughts, feelings, and behaviors of individuals. These include forces such as attitudes, child-rearing practices,
discrimination and prejudice, ethnic and racial identity, gender roles and norms, family and kinship structures,
power dynamics, regional differences, religious beliefs and practices, rituals, and taboos. Several subfields within
psychology seek to examine these sociocultural factors that influence human mental states and behavior; among
these are social psychology, cultural psychology, cultural-historical psychology, and cross-cultural psychology.
There are many interesting examples of social
psychological research, and you will read about many of
these in a later in this textbook. Until then, you will be
introduced to one of the most controversial psychological
studies ever conducted. Stanley Milgram was an American
social psychologist who is most famous for research that he
conducted on obedience. After the Holocaust, in 1961, a
Nazi war criminal, Adolf Eichmann, who was accused of
committing mass atrocities, was put on trial. Many people
wondered how German soldiers were capable of torturing
prisoners in concentration camps, and they were
unsatisfied with the excuses given by soldiers that they
were simply following orders. At the time, most
psychologists agreed that few people would be willing to
inflict such extraordinary pain and suffering, simply because
they were obeying orders. Milgram decided to conduct
research to determine whether or not this was true.
As you will read later in the text, Milgram found that nearly
two-thirds of his participants were willing to deliver what
they believed to be lethal shocks to another person, simply
because they were instructed to do so by an authority figure
(in this case, a man dressed in a lab coat). This was in spite
of the fact that participants received payment for simply
showing up for the research study and could have chosen
not to inflict pain or more serious consequences on another
person by withdrawing from the study. No one was actually
hurt or harmed in any way, Milgram’s experiment was a
clever ruse that took advantage of research confederates,
those who pretend to be participants in a research study
who are actually working for the researcher and have clear,
specific directions on how to behave during the research
study (Hock, 2009). Milgram’s and others’ studies that
involved deception and potential emotional harm to study
participants catalyzed the development of ethical guidelines
for conducting psychological research that discourage the
use of deception of research subjects, unless it can be
argued not to cause harm and, in general, requiring informed consent of participants.
Personality Psychology
Another major field of study within the social and personality domain is, of course, personality psychologypersonality psychology.
Personality refers to the long-standing traits and patterns that propel individuals to consistently think, feel, and
behave in specific ways. Our personality is what makes us unique individuals. Each person has an idiosyncratic
pattern of enduring, long-term characteristics, and a manner in which they interact with other individuals and the
world around them. Our personalities are thought to be long-term, stable, and not easily changed. Personality
psychology focuses on

Each of the dimensions of the Five Factor model is shown in this figure. The provided description would describe
someone who scored highly on that given dimension. Someone with a lower score on a given dimension could be
described in opposite terms.
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• construction of a coherent picture of the individual and their major psychological processes.
• investigation of individual psychological differences.
• investigation of human nature and psychological similarities between individuals.
Several individuals (e.g., Freud and Maslow) that we have already discussed in our historical overview of
psychology, and the American psychologist Gordon Allport, contributed to early theories of personality. These
early theorists attempted to explain how an individual’s personality develops from his or her given perspective.
For example, Freud proposed that personality arose as conflicts between the conscious and unconscious parts of
the mind were carried out over the lifespan. Specifically, Freud theorized that an individual went through various
psychosexual stages of development. According to Freud, adult personality would result from the resolution of
various conflicts that centered on the migration of erogenous (or sexual pleasure-producing) zones from the oral
(mouth) to the anus to the phallus to the genitals. Like many of Freud’s theories, this particular idea was
controversial and did not lend itself to experimental tests (Person, 1980).
More recently, the study of personality has taken on a more quantitative approach. Rather than explaining how
personality arises, research is focused on identifying personality traitspersonality traits, measuring these traits, and determining
how these traits interact in a particular context to determine how a person will behave in any given situation.
Personality traits are relatively consistent patterns of thought and behavior, and many have proposed that five trait
dimensions are sufficient to capture the variations in personality seen across individuals. These five dimensions
are known as the “Big Five” or the Five Factor model, and include dimensions of conscientiousness,
agreeableness, neuroticism, openness, and extraversion (shown below). Each of these traits has been
demonstrated to be relatively stable over the lifespan (e.g., Rantanen, Metsäpelto, Feldt, Pulkinnen, and Kokko,
2007; Soldz & Vaillant, 1999; McCrae & Costa, 2008) and is influenced by genetics (e.g., Jang, Livesly, and
Vernon, 1996).

Figure 5. Each of the dimensions of the Five Factor model is shown in this figure. The provided description would describe
someone who scored highly on that given dimension. Someone with a lower score on a given dimension could be described in
opposite terms.
The Mental and Physical Health Domain
This domain of psychology is what many people think of when they think about psychology—mental disorders and
counseling. This includes the study of abnormal psychology, with its focus on abnormal thoughts and behaviors,
as well as counseling and treatment methods, and recommendations for coping with stress and living a healthy
life.

The names and classifications of mental disorders are listed in the Diagnostic and Statistical Manual of Mental
Disorders (DSM). The DSM is currently in its 5th edition (DSM-V) and has been designed for use in a wide variety
of contexts and across clinical settings (including inpatient, outpatient, partial hospital, clinic, private practice, and
primary care). The diagnostic manual includes a total of 237 specific diagnosable disorders, each described in
detail, including its symptoms, prevalence, risk factors, and comorbidity. Over time, the number of diagnosable
conditions listed in the DSM has grown steadily, prompting criticism from some. Nevertheless, the diagnostic
criteria in the DSM are more explicit than those of any other system, which makes the DSM system highly
desirable for both clinical diagnosis and research.
Figure 6. Lifetime prevalence rates for major psychological disorders.
Clinical Psychology
Clinical psychologyClinical psychology is the area of psychology that focuses on the diagnosis and treatment of psychological
disorders and other problematic patterns of behavior. As such, it is generally considered to be a more applied
area within psychology; however, some clinicians are also actively engaged in scientific research. Counseling
psychology is a similar discipline that focuses on emotional, social, vocational, and health-related outcomes in
individuals who are considered psychologically healthy. As mentioned earlier, both Freud and Rogers provided
perspectives that have been influential in shaping how clinicians interact with people seeking psychotherapy.
While aspects of the psychoanalytic theory are still found among some of today’s therapists who are trained from
a psychodynamic perspective, Roger’s ideas about client-centered therapy have been especially influential in
shaping how many clinicians operate. Furthermore, both behaviorism and the cognitive revolution have shaped
clinical practice in the forms of behavioral therapy, cognitive therapy, and cognitive-behavioral therapy. Issues
related to the diagnosis and treatment of psychological disorders and problematic patterns of behavior will be
discussed in detail later in this textbook.

Figure 7. Cognitive-behavioral therapists take cognitive
processes and behaviors into account when providing
psychotherapy. This is one of several strategies that may
be used by practicing clinical psychologists.
By far, this is the area of psychology that receives the most
attention in popular media, and many people mistakenly
assume that all psychology is clinical psychology.
Health Psychology
Health psychology focuses on how health is affected by the
interaction of biological, psychological, and sociocultural
factors. This particular approach is known as the
biopsychosocial modelbiopsychosocial model. Health psychologists are interested
in helping individuals achieve better health through public
policy, education, intervention, and research. Health
psychologists might conduct research that explores the
relationship between one’s genetic makeup, patterns of
behavior, relationships, psychological stress, and health.
They may research effective ways to motivate people to
address patterns of behavior that contribute to poorer
health (MacDonald, 2013).

Figure 8. The biopsychosocial model suggests that health/illness is determined by an interaction of these three factors.
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Other Psychological
Subfields
Industrial-Organizational Psychology
Industrial-Organizational psychology (I-O psychology) is a subfield of psychology that applies psychological
theories, principles, and research findings in industrial and organizational settings. I-O psychologists are often
involved in issues related to personnel management, organizational structure, and workplace environment.
Businesses often seek the aid of I-O psychologists to make the best hiring decisions as well as to create an
environment that results in high levels of employee productivity and efficiency. In addition to its applied nature, I-O
psychology also involves conducting scientific research on behavior within I-O settings (Riggio, 2013).
Sport and Exercise Psychology
Researchers in sport and exercise psychologysport and exercise psychology study the psychological aspects of sport performance, including
motivation and performance anxiety, and the effects of sport on mental and emotional wellbeing. Research is also
conducted on similar topics as they relate to physical exercise in general. The discipline also includes topics that
are broader than sport and exercise but that are related to interactions between mental and physical performance
under demanding conditions, such as fire fighting, military operations, artistic performance, and surgery.
Forensic Psychology
Forensic psychologyForensic psychology is a branch of psychology that deals questions of psychology as they arise in the context of
the justice system. For example, forensic psychologists (and forensic psychiatrists) will assess a person’s
competency to stand trial, assess the state of mind of a defendant, act as consultants on child custody cases,
consult on sentencing and treatment recommendations, and advise on issues such as eyewitness testimony and
children’s testimony (American Board of Forensic Psychology, 2014). In these capacities, they will typically act as
expert witnesses, called by either side in a court case to provide their research- or experience-based opinions. As
expert witnesses, forensic psychologists must have a good understanding of the law and provide information in
the context of the legal system rather than just within the realm of psychology. Forensic psychologists are also
used in the jury selection process and witness preparation. They may also be involved in providing psychological
treatment within the criminal justice system. Criminal profilers are a relatively small proportion of psychologists
that act as consultants to law enforcement.

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Check out the APA website for more information on psychological subfields and possible career paths here.
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GLOSSARYGLOSSARY
American Psychological Association:American Psychological Association: professional organization representing psychologists in the United States
biopsychology:biopsychology: study of how biology influences behavior
biopsychosocial model:biopsychosocial model: perspective that asserts that biology, psychology, and social factors interact to
determine an individual’s health
clinical psychology:clinical psychology: area of psychology that focuses on the diagnosis and treatment of psychological disorders
and other problematic patterns of behavior
cognitive psychologycognitive psychology: area of psychology that focuses on studying thoughts and their relationship to our
experiences and actions
developmental psychology:developmental psychology: scientific study of development across a lifespan
forensic psychology:forensic psychology: area of psychology that applies the science and practice of psychology to issues within
and related to the justice system
personality psychology:personality psychology: study of patterns of thoughts and behaviors that make each individual unique
personality trait:personality trait: consistent pattern of thought and behavior
sport and exercise psychology:sport and exercise psychology: area of psychology that focuses on the interactions between mental and
emotional factors and physical performance in sports, exercise, and other activities
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http://www.apa.org/careers/resources/guides/careers.aspx

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CAREERS IN PSYCHOLOGY
What you’ll learn to do: describe the value of psychology and
possible careers paths for those who study psychology
Figure 1. An Army psychologist reviewing medical information.
Generally, academic careers in psychology require doctoral degrees. However, there are a number of
nonacademic career options for people who have master’s degrees in psychology. While people with bachelor’s
degrees in psychology have more limited psychology-related career options, the skills acquired as a function of an

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Figure 1. Doctoral degrees are generally conferred in
formal ceremonies involving special attire and rites.
(credit: Public Affairs Office Fort Wainwright)
LINK TO LEARNINGLINK TO LEARNING
Watch this brief video that describes some of the questions a student should consider before deciding to major
in psychology.
undergraduate education in psychology are useful in a variety of work contexts and are applicable to a wide
variety of careers. Basically, studying psychology is never a bad choice!
LEARNING OBJECTIVESLEARNING OBJECTIVES
• Explain why an education in psychology is valuable
• Describe educational requirements and career options for the study of psychology
Merits of an Education in
Psychology
Often, students take their first psychology course because
they are interested in helping others and want to learn more
about themselves and why they act the way they do.
Sometimes, students take a psychology course because it
either satisfies a general education requirement or is
required for a program of study such as nursing or pre-med.
Many of these students develop such an interest in the area
that they go on to declare psychology as their major. As a
result, psychology is one of the most popular majors on
college campuses across the United States (Johnson &
Lubin, 2011). A number of well-known individuals were
psychology majors. Just a few famous names on this list
are Facebook’s creator Mark Zuckerberg, television
personality and political satirist Jon Stewart, actress Natalie Portman, and filmmaker Wes Craven (Halonen,
2011). About 6 percent of all bachelor degrees granted in the United States are in the discipline of psychology
(U.S. Department of Education, 2013).
An education in psychology is valuable for a number of reasons. Psychology students hone critical thinking skills
and are trained in the use of the scientific method. Critical thinking is the active application of a set of skills to
information for the understanding and evaluation of that information. The evaluation of information—assessing its
reliability and usefulness— is an important skill in a world full of competing “facts,” many of which are designed to
be misleading. For example, critical thinking involves maintaining an attitude of skepticism, recognizing internal
biases, making use of logical thinking, asking appropriate questions, and making observations. Psychology
students also can develop better communication skills during the course of their undergraduate coursework
(American Psychological Association, 2011). Together, these factors increase students’ scientific literacy and
prepare students to critically evaluate the various sources of information they encounter.
In addition to these broad-based skills, psychology students come to understand the complex factors that shape
one’s behavior. They appreciate the interaction of our biology, our environment, and our experiences in
determining who we are and how we will behave. They learn about basic principles that guide how we think and
behave, and they come to recognize the tremendous diversity that exists across individuals and across cultural
boundaries (American Psychological Association, 2011).

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THINK IT OVERTHINK IT OVER
Why are you taking this course? What do you hope to learn about during this course?
Careers in Psychology
Psychologists can work in many different places doing many different things. In general, anyone wishing to
continue a career in psychology at a 4-year institution of higher education will have to earn a doctoral degree in
psychology for some specialties and at least a master’s degree for others. In most areas of psychology, this
means earning a PhD in a relevant area of psychology. Literally, PhD refers to a doctor of philosophy degree, but
here, philosophy does not refer to the field of philosophy per se. Rather, philosophy in this context refers to many
different disciplinary perspectives that would be housed in a traditional college of liberal arts and sciences.

The requirements to earn a PhD vary from country to country and even from school to school, but usually,
individuals earning this degree must complete a dissertation. A dissertation is essentially a long research paper or
bundled published articles describing research that was conducted as a part of the candidate’s doctoral training.
In the United States, a dissertation generally has to be defended before a committee of expert reviewers before
the degree is conferred. Once someone earns her PhD, she may seek a faculty appointment at a college or
university. Being on the faculty of a college or university often involves dividing time between teaching, research,
and service to the institution and profession. The amount of time spent on each of these primary responsibilities
varies dramatically from school to school, and it is not uncommon for faculty to move from place to place in
search of the best personal fit among various academic environments. The previous section detailed some of the
major areas that are commonly represented in psychology departments around the country; thus, depending on
the training received, an individual could be anything from a biological psychologist to a clinical psychologist in an
academic setting.
Figure 2. Individuals earning a PhD in psychology have a range of employment options.
Other Careers in Academic Settings
Often times, schools offer more courses in psychology than their full-time faculty can teach. In these cases, it is
not uncommon to bring in an adjunct faculty member or instructor. Adjunct faculty members and instructors
usually have an advanced degree in psychology, but they often have primary careers outside of academia and
serve in this role as a secondary job. Alternatively, they may not hold the doctoral degree required by most 4-year
institutions and use these opportunities to gain experience in teaching. Furthermore, many 2-year colleges and
schools need faculty to teach their courses in psychology. In general, many of the people who pursue careers at
these institutions have master’s degrees in psychology, although some PhDs make careers at these institutions
as well.
Some people earning PhDs may enjoy research in an academic setting. However, they may not be interested in
teaching. These individuals might take on faculty positions that are exclusively devoted to conducting research.
This type of position would be more likely an option at large, research-focused universities.

In some areas in psychology, it is common for individuals who have recently earned their PhD to seek out
positions in postdoctoral training programs that are available before going on to serve as faculty. In most cases,
young scientists will complete one or two postdoctoral programs before applying for a full-time faculty position.
Postdoctoral training programs allow young scientists to further develop their research programs and broaden
their research skills under the supervision of other professionals in the field.
Career Options Outside of Academics
Individuals who wish to become practicing clinical psychologists have another option for earning a doctoral
degree, which is known as a PsyD. A PsyD is a doctor of psychology degree that is increasingly popular among
individuals interested in pursuing careers in clinical psychology. PsyD programs generally place less emphasis on
research-oriented skills and focus more on application of psychological principles in the clinical context (Norcorss
& Castle, 2002).
Regardless of whether earning a PhD or PsyD, in most states, an individual wishing to practice as a licensed
clinical or counseling psychologist may complete postdoctoral work under the supervision of a licensed
psychologist. Within the last few years, however, several states have begun to remove this requirement, which
would allow someone to get an earlier start in his career (Munsey, 2009). After an individual has met the state
requirements, his credentials are evaluated to determine whether he can sit for the licensure exam. Only
individuals that pass this exam can call themselves licensed clinical or counseling psychologists (Norcross, n.d.).
Licensed clinical or counseling psychologists can then work in a number of settings, ranging from private clinical
practice to hospital settings. It should be noted that clinical psychologists and psychiatrists do different things and
receive different types of education. While both can conduct therapy and counseling, clinical psychologists have a
PhD or a PsyD, whereas psychiatrists have a doctor of medicine degree (MD). As such, licensed clinical
psychologists can administer and interpret psychological tests, while psychiatrists can prescribe medications.
Individuals earning a PhD can work in a variety of settings, depending on their areas of specialization. For
example, someone trained as a biopsychologist might work in a pharmaceutical company to help test the efficacy
of a new drug. Someone with a clinical background might become a forensic psychologist and work within the
legal system to make recommendations during criminal trials and parole hearings, or serve as an expert in a court
case.
While earning a doctoral degree in psychology is a lengthy process, usually taking between 5–6 years of graduate
study (DeAngelis, 2010), there are a number of careers that can be attained with a master’s degree in
psychology. People who wish to provide psychotherapy can become licensed to serve as various types of
professional counselors (Hoffman, 2012). Relevant master’s degrees are also sufficient for individuals seeking
careers as school psychologists (National Association of School Psychologists, n.d.), in some capacities related
to sport psychology (American Psychological Association, 2014), or as consultants in various industrial settings
(Landers, 2011, June 14). Undergraduate coursework in psychology may be applicable to other careers such as
psychiatric social work or psychiatric nursing, where assessments and therapy may be a part of the job.
As mentioned in the opening section of this chapter, an undergraduate education in psychology is associated with
a knowledge base and skill set that many employers find quite attractive. It should come as no surprise, then, that
individuals earning bachelor’s degrees in psychology find themselves in a number of different careers, as shown
in the table. Examples of a few such careers can involve serving as case managers, working in sales, working in
human resource departments, and teaching in high schools. The rapidly growing realm of healthcare professions
is another field in which an education in psychology is helpful and sometimes required. For example, the Medical
College Admission Test (MCAT) exam that people must take to be admitted to medical school now includes a
section on the psychological foundations of behavior.

LINK TO LEARNINGLINK TO LEARNING
Watch a brief video describing some of the career options available to people earning bachelor’s degrees in
psychology.
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TRY ITTRY IT
Table 1. Top Occupations Employing Graduates with a BA in Psychology (Fogg, Harrington, Harrington, &
Shatkin, 2012)
RankingRanking OccupationOccupation
1 Mid- and top-level management (executive, administrator)
2 Sales
3 Social work
4 Other management positions
5 Human resources (personnel, training)
6 Other administrative positions
7 Insurance, real estate, business
8 Marketing and sales
9 Healthcare (nurse, pharmacist, therapist)
10 Finance (accountant, auditor)

http://careerplanning.about.com/video/Careers-for-Psychology-Majors.htm

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GLOSSARYGLOSSARY
dissertation:dissertation: long research paper about research that was conducted as a part of the candidate’s doctoral
training
PhD:PhD: (doctor of philosophy) doctoral degree conferred in many disciplinary perspectives housed in a traditional
college of liberal arts and sciences
postdoctoral training program:postdoctoral training program: allows young scientists to further develop their research programs and broaden
their research skills under the supervision of other professionals in the field
PsyD:PsyD: (doctor of psychology) doctoral degree that places less emphasis on research-oriented skills and focuses
more on application of psychological principles in the clinical context
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THINK IT OVERTHINK IT OVER
Which of the career options described in this section is most appealing to you?
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PUTTING IT TOGETHER: PSYCHOLOGICAL
FOUNDATIONS
LEARNING OBJECTIVESLEARNING OBJECTIVES
In this module, you learned to

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WORD AVERSIONWORD AVERSION
People Magazine—psycholinguistics’ most trusted lexicon—defines “moist” as “the most cringeworthy word” in
American English. When they asked some of the sexiest men alivesexiest men alive to try and make the word sound sexy, it was
pretty clear they could not. One viewer respondedOne viewer responded that the video was “pure sadism” and that the only way to
recover would be to “go Oedipal and gouge your eyes out.”
There is something interesting going on with this word. Several people have documented the weirdnessweirdness of
“moist”, speculatedspeculated on why it is aversive, or used the phenomenon for comedic effect.
In a recent series of studiesseries of studies published in PLOS ONE, several members of my lab and I sought to answer some
initial questions about word aversion. Specifically:
1.1. How prevalent is an aversion to “moist” and who’s averse?
2.2. What does it mean to be averse to a word?
3.3. And, what makes a word aversive?
Five experiments, conducted over about four years, with almost 2,500 participants from the general population
of American English speakers provide some answers.
How prevalent is an aversion to “moist” and who’s averse?
On average, about 18 percent of our participants identified as categorically averse to the word. Women,
younger people, and those with more education, who tended to score higher on measures of disgust toward
bodily function and neuroticism (a personality trait characterized by increased feelings of anxiety, worry, anger
and guilt), were particularly likely to find the word unpleasant.
• describe the evolution of psychology and the major pioneers in the field
• identify the various approaches, fields, and subfields of psychology along with their major concepts
and important figures
• describe the value of psychology and possible careers paths for those who study psychology
Psychology is a rapidly growing and ever-evolving field of study. In this module, you learned about its roots in
early philosophy and the development of psychology as a distinct field of study in the late 1800s. Since that time,
various schools of psychology have dominated the scene at different points in time, from structuralism and
functionalism, to Freud’s psychodynamic theory, behaviorism, humanism, and the cognitive revolution. In modern
psychology, researchers and practitioners consider some of these historical approaches but also approach the
study of mind and behavior through a variety of lenses, including biological, cognitive, developmental, social, and
health perspectives. Watch the following Crash Course Psychology video for a good recap of the topics covered
in this module:
Consider a fascinating example of psychological research conducted by is an Assistant Professor of Cognitive
Psychology at Oberlin College, Paul Thibodeau. His focus is on language, specifically how people utilize
metaphors and analogies, but he did one study on word aversion that he explains in his own words in the
following example. As you read it, consider the breadth of coverage that psychologists cover as well as the
importance of the scientific method and research to the investigative process. We’ll learn more about experiments
and psychological research in the next module, but if you could design a psychological study based on the topics
that piqued your interested in this text so far, what would it be? Where do your interests lie? Remember, there are
nearly endless possibilities for research within the vast field of psychology, and studying the subject will serve to
your advantage, no matter your chosen field or career path.

http://www.refinery29.com/2013/11/57779/people-sexiest-men-moist-video

https://www.newyorker.com/culture/culture-desk/words-came-in-marked-for-death

Literary moist aversion

http://dx.plos.org/10.1371/journal.pone.0153686

Controlling for these factors, we found no differences in a person’s likelihood of finding “moist” aversive based
on their political ideology, religiosity, disgust toward sex, or any other personality variables.
What makes a word aversive?
We considered three possible reasons for moist-aversion:
1. Sound.1. Sound. The sound of the word itself may be the cause of peoples’ aversion to “moist.” Some work in
psychology has found that certain sounds are inherently unpleasant—like fingernails scratching a chalkboard.
Other work has found evidence of a “facial feedback hypothesis:” “moist” may be aversive because saying the
word engages the same facial muscles that contract when we see (or smell or hear) something disgusting. This
may, in fact, cause people to feel disgusted by saying the word “moist:” patterns of facial muscle constriction
not only signal our emotional states to other people, we also learn about ourselves from our unconscious
physiological responses to stimuli in the world.
2. Connotation.2. Connotation. An alternative possibility is that the word is associated in people’s minds with other words or
things things that they already find disgusting, like vomit, phlegm, or aspects of sex. Of course, “moist” also has
some positive connotations—who doesn’t love a moist piece of chocolate cake? So a related possibility might
be that the word is aversive because it simultaneously calls to mind positive and negative associations. Maybe
when someone encounters the word they are hit with images of cake and sweaty armpits—not an ideal
combination.
3. Social transmission.3. Social transmission. A final possibility is that the word may have become aversive because of the attention it
has received in popular and social media. Word aversion may result from a conscious process of thinking about
how certain words are gross. This would suggest that there is a “good” psychological reason for the
aversion—that it is grounded in the sound or connotation of the word—but that it is triggered by deliberation and
may spread like a virus. Anecdotal evidence for this possibility comes from the growing number of people who
seem to find the word unpalatable: as the word gains attention, more and more people seem to find the word
aversive. Alternatively, moist-aversion may just be a fad. If so, the “good” psychological reason for the
phenomenon might simply be to identify oneself as part of a group—a group of people who find “moist”
cringeworthy.
The experiments provided the most support for a combination of the second and third possibilities: that aversion
to “moist” may spread socially but it is also grounded in feelings of disgust toward bodily functions.
Here’s the evidence for why moist-aversion seems to be tied to disgust toward bodily function. First, recall that
people who scored higher on a measure of disgust toward bodily function were more likely to find “moist”
aversive. Second, people who identified as categorically averse to “moist” also found words like “phlegm” and
“vomit” more aversive than people who didn’t have a strong unpleasant reaction to “moist.” In contrast, moist-
averse participants were not more sensitive to words that had similar phonological properties to “moist” like
“foist,” “hoist,” or “rejoiced” or to words related to sex like “vagina” and “penis” (or a variety of other words
related to sex that you can find in the paper).

Third, when we used a common statistical technique (latent semantic analysis) to figure out how similar in
meaning the words in our set were to “moist,” the result was a good predictor of peoples’ perceptions of word-
averseness. That is, moist-averse participants showed a stronger aversion to words that were related in
meaning to “moist,” like “wet” and “damp.” There was no difference in ratings of aversiveness of words like
“hoist” and “love” that are less similar in meaning to “moist.”
Interestingly, participants’ speculation on the cause of moist-aversion was inconsistent with the behavioral data.
Often, moist-averse participants pointed to the sound of the word as the source of their aversion. “The ‘oy’

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sound juxtaposed to ‘ss’ and ‘tt.’ It’s not a word that sounds pleasant. Neither does hoist or foist,” wrote one
participant. Non-averse participants pointed to the word’s association with sex: “It reminds people of sex and
vaginas.” This kind of data from introspection can be misleading. There is a long history in psychology showing
that people regularly don’t know why they think and behave the way that they do. In this case, both groups were
wrong: people who identified as averse to “moist” may think the sound of the word itself is the cause of their
aversion because their reaction is fast and visceral—so it must have something to do with the sound of the
word. Similarly, although “moist” may have associations to sex, these associations don’t seem to be the primary
cause of moist-aversion.
The strongest evidence that moist-aversion is transmitted socially and may be triggered by a process of
conscious deliberation came from one of our studies that was designed to induce an aversion to the word. One
group of people watched the video that was made by People Magazine, while another watched a “control” video
that showed actors using the word “moist” to describe the taste of cake. After watching the cringe-inducing
video, people considered “moist” not only more aversive, but said that it was a word they used relatively
infrequently and that the word had a more negative connotation. In other words, watching the video that made
“moist” seem aversive shifted the entire profile of the word to be more consistent with the perceptions of people
who were already averse to the word.
What do we learn from these studies?
There are a few important lessons to be learned from these studies. Two are fairly obvious: we now have a
better sense of what makes the word “moist” aversive and another demonstration that we’re not particularly
good at reflecting accurately on why we think what we think.
More relevant to broader theories in psychology, the work has implications for theories of language processing
and the psychology of disgust. Emotional language is processed differently than “neutral” language: it grabs our
attention, engages different parts of the brain, and is more likely to be remembered. This can be good or bad:
cake mixes that advertise themselves as “moist” may make some people more likely to buy them because they
catch our eye, but they may make us less likely to buy them because of the word’s association with disgusting
bodily function (an open question).
Disgust is adaptive. If we didn’t have an instinct to run away from vomit and diarrhea, disease would spread
more easily. But is this instinct biological or do we learn it? Does our culture shape what we find disgusting?
This is a complex and nuanced question. Significant work is needed to answer it definitively. But the present
studies suggest that, when it comes to the disgust that is elicited by words like “moist,” there is an important
cultural component—the symbols we use to communicate with one another can become contaminated and
elicit disgust by virtue of their association with bodily functions.
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DISCUSSION: FOUNDATIONS OF PSYCHOLOGY
Perspectives in Psychology
In this discussion, you will post a minimum THREE times. First, in a primary post of between 200 and 300 words,
then at least twice on other posts in the class (of at least 75 words each).

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Step 1Step 1: In this module, you learned about the five main psychological domains and also covered some of the main
perspectives in psychology. Think about some of the various perspectives you learned about (including
psychoanalysis, behaviorism, cognitive psychology, humanism, and the biological approach), and explain how an
alien psychologist from another planet might explain the following human behaviors:
1. Why do people cut or shave hair from their bodies (and why does it vary by sex, age, groups, etc.)?
2. Why do children in an elementary school walk in a line when going to class?
3. Why are people physically aggressive towards each other (and why might males might be observed
doing so more than females)?
Explain each of the three behaviors with a DIFFERENT perspective. Give a well-founded explanation of how a
psychologist would explain that behavior from that particular perspective.
Next, write a summary paragraph about which psychological perspective most resonates with you, and why. If
you were to practice psychology someday, either as a therapist, counselor, teacher, researcher, or in some other
capacity, which perspective do you think you might emphasize?
Step 2Step 2: Comment, in posts of at least 75-100 words, on TWO other posts in the discussion. These responses
should add to the conversation and contribute to a deeper understanding of the psychological perspective.
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MODULE 2: PSYCHOLOGICAL
RESEARCH
WHY IT MATTERS: PSYCHOLOGICAL RESEARCH
How does television content impact children’s behavior? (credit: modification of work by “antisocialtory”/Flickr)
Have you ever wondered whether the violence you see on television affects your behavior? Are you more likely to
behave aggressively in real life after watching people behave violently in dramatic situations on the screen? Or,
could seeing fictional violence actually get aggression out of your system, causing you to be more peaceful? How
are children influenced by the media they are exposed to? A psychologist interested in the relationship between
behavior and exposure to violent images might ask these very questions.
The topic of violence in the media today is contentious. Since ancient times, humans have been concerned about
the effects of new technologies on our behaviors and thinking processes. The Greek philosopher Socrates, for
example, worried that writing—a new technology at that time—would diminish people’s ability to remember
because they could rely on written records rather than committing information to memory. In our world of quickly
changing technologies, questions about the effects of media continue to emerge. Is it okay to talk on a cell phone
while driving? Are headphones good to use in a car? What impact does text messaging have on reaction time
while driving? These are types of questions that psychologist David Strayer asks in his lab. Watch this short video
to see how he utilizes the scientific method to reach important conclusions regarding technology and driving
safety.

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How can we go about finding answers that are supported not by mere opinion, but by evidence that we can all
agree on? The findings of psychological research can help us navigate issues like this.
AnswerAnswer
American Academy of Pediatrics, American Academy of Child & Adolescent Psychiatry, American Psychological
Association, American Medical Association, American Academy of Family Physicians, American Psychiatric
Association. (2000). Joint statement on the impact of entertainment violence on children. Retrieved from
http://www2.aap.org/advocacy/releases/jstmtevc.htm.
American Cancer Society. (n.d.). History of the cancer prevention studies. Retrieved from http://www.cancer.org/
research/researchtopreventcancer/history-cancer-prevention-study
American Psychological Association. (2009). Publication Manual of the American Psychological Association (6th
ed.). Washington, DC: Author.
American Psychological Association. (n.d.). Research with animals in psychology. Retrieved from
https://www.apa.org/research/responsible/research-animals
Arnett, J. (2008). The neglected 95%: Why American psychology needs to become less American. American
Psychologist, 63(7), 602–614.
Barton, B. A., Eldridge, A. L., Thompson, D., Affenito, S. G., Striegel-Moore, R. H., Franko, D. L., . . . Crockett, S.
J. (2005). The relationship of breakfast and cereal consumption to nutrient intake and body mass index: The
national heart, lung, and blood institute growth and health study. Journal of the American Dietetic Association,
105(9), 1383–1389. Retrieved from http://dx.doi.org/10.1016/j.jada.2005.06.003
Chwalisz, K., Diener, E., & Gallagher, D. (1988). Autonomic arousal feedback and emotional experience:
Evidence from the spinal cord injured. Journal of Personality and Social Psychology, 54, 820–828.
Clayton, R. R., Cattarello, A. M., & Johnstone, B. M. (1996). The effectiveness of Drug Abuse Resistance
Education (Project DARE): 5-year follow-up results. Preventive Medicine: An International Journal Devoted to
Practice and Theory, 25(3), 307–318. doi:10.1006/pmed.1996.0061
D.A.R.E. (n.d.). D.A.R.E. is substance abuse prevention education and much more! [About page] Retrieved from
http://www.dare.org/about-d-a-r-e/
Dominus, S. (2011, May 25). Could conjoined twins share a mind? New York Times Sunday Magazine. Retrieved
from http://www.nytimes.com/2011/05/29/magazine/could-conjoined-twins-share-a-mind.html?_r=5&hp&
Ennett, S. T., Tobler, N. S., Ringwalt, C. L., & Flewelling, R. L. (1994). How effective is drug abuse resistance
education? A meta-analysis of Project DARE outcome evaluations. American Journal of Public Health, 84(9),
1394–1401. doi:10.2105/AJPH.84.9.1394
Fanger, S. M., Frankel, L. A., & Hazen, N. (2012). Peer exclusion in preschool children’s play: Naturalistic
observations in a playground setting. Merrill-Palmer Quarterly, 58, 224–254.
Fiedler, K. (2004). Illusory correlation. In R. F. Pohl (Ed.), Cognitive illusions: A handbook on fallacies and biases
in thinking, judgment and memory (pp. 97–114). New York, NY: Psychology Press.
Frantzen, L. B., Treviño, R. P., Echon, R. M., Garcia-Dominic, O., & DiMarco, N. (2013). Association between
frequency of ready-to-eat cereal consumption, nutrient intakes, and body mass index in fourth- to sixth-grade low-
income minority children. Journal of the Academy of Nutrition and Dietetics, 113(4), 511–519.
Harper, J. (2013, July 5). Ice cream and crime: Where cold cuisine and hot disputes intersect. The Times-
Picaune. Retrieved from http://www.nola.com/crime/index.ssf/2013/07/ice_cream_and_crime_where_hot.html

Jenkins, W. J., Ruppel, S. E., Kizer, J. B., Yehl, J. L., & Griffin, J. L. (2012). An examination of post 9-11 attitudes
towards Arab Americans. North American Journal of Psychology, 14, 77–84.
Jones, J. M. (2013, May 13). Same-sex marriage support solidifies above 50% in U.S. Gallup Politics. Retrieved
from http://www.gallup.com/poll/162398/sex-marriage-support-solidifies-above.aspx
Kobrin, J. L., Patterson, B. F., Shaw, E. J., Mattern, K. D., & Barbuti, S. M. (2008). Validity of the SAT for
predicting first-year college grade point average (Research Report No. 2008-5). Retrieved from
https://research.collegeboard.org/sites/default/files/publications/2012/7/researchreport-2008-5-validity-sat-
predicting-first-year-college-grade-point-average
Lewin, T. (2014, March 5). A new SAT aims to realign with schoolwork. New York Times. Retreived from
http://www.nytimes.com/2014/03/06/education/major-changes-in-sat-announced-by-college-board.html.
Lowcock, E. C., Cotterchio, M., Anderson, L. N., Boucher, B. A., & El-Sohemy, A. (2013). High coffee intake, but
not caffeine, is associated with reduced estrogen receptor negative and postmenopausal breast cancer risk with
no effect modification by CYP1A2 genotype. Nutrition and Cancer, 65(3), 398–409. doi:10.1080/
01635581.2013.768348
Lowry, M., Dean, K., & Manders, K. (2010). The link between sleep quantity and academic performance for the
college student. Sentience: The University of Minnesota Undergraduate Journal of Psychology, 3(Spring), 16–19.
Retrieved from http://www.psych.umn.edu/sentience/files/SENTIENCE_Vol3
Lynam, D. R., Milich, R., Zimmerman, R., Novak, S. P., Logan, T. K., Martin, C., . . . Clayton, R. (1999). Project
DARE: No effects at 10-year follow-up. Journal of Consulting and Clinical Psychology, 67(4), 590–593.
doi:10.1037/0022-006X.67.4.590
McKie, R. (2010, June 26). Chimps with everything: Jane Goodall’s 50 years in the jungle. The Guardian.
Retrieved from http://www.theguardian.com/science/2010/jun/27/jane-goodall-chimps-africa-interview
Offit, P. (2008). Autism’s false prophets: Bad science, risky medicine, and the search for a cure. New York:
Columbia University Press.
Perkins, H. W., Haines, M. P., & Rice, R. (2005). Misperceiving the college drinking norm and related problems: A
nationwide study of exposure to prevention information, perceived norms and student alcohol misuse. J. Stud.
Alcohol, 66(4), 470–478.
Rimer, S. (2008, September 21). College panel calls for less focus on SATs. The New York Times. Retrieved
from http://www.nytimes.com/2008/09/22/education/22admissions.html?_r=0
Ringwalt, C., Ennett, S. T., & Holt, K. D. (1991). An outcome evaluation of Project DARE (Drug Abuse Resistance
Education). Health Education Research, 6(3), 327–337. doi:10.1093/her/6.3.327
Rothstein, J. M. (2004). College performance predictions and the SAT. Journal of Econometrics, 121, 297–317.
Rotton, J., & Kelly, I. W. (1985). Much ado about the full moon: A meta-analysis of lunar-lunacy research.
Psychological Bulletin, 97(2), 286–306. doi:10.1037/0033-2909.97.2.286
Santelices, M. V., & Wilson, M. (2010). Unfair treatment? The case of Freedle, the SAT, and the standardization
approach to differential item functioning. Harvard Education Review, 80, 106–134.
Sears, D. O. (1986). College sophomores in the laboratory: Influences of a narrow data base on social
psychology’s view of human nature. Journal of Personality and Social Psychology, 51, 515–530.
Tuskegee University. (n.d.). About the USPHS Syphilis Study. Retrieved from http://www.tuskegee.edu/about_us/
centers_of_excellence/bioethics_center/about_the_usphs_syphilis_study.aspx.

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THE SCIENTIFIC METHOD
What you’ll learn to do: define and apply the scientific method to
psychology
Scientists are engaged in explaining and understanding how the world around them works, and they are able to
do so by coming up with theories that generate hypotheses that are testable and falsifiable. Theories that stand
up to their tests are retained and refined, while those that do not are discarded or modified. In this way, research
enables scientists to separate fact from simple opinion. Having good information generated from research aids in
making wise decisions both in public policy and in our personal lives. In this section, you’ll see how psychologists
use the scientific method to study and understand behavior.
LEARNING OBJECTIVESLEARNING OBJECTIVES
• Explain the steps of the scientific method
• Describe why the scientific method is important to psychology
• Summarize the processes of informed consent and debriefing

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Figure 1. Some of our ancestors, across the world and
over the centuries, believed that trephination—the
practice of making a hole in the skull, as shown
here—allowed evil spirits to leave the body, thus curing
mental illness and other disorders. (credit:
“taiproject”/Flickr)
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TRY ITTRY IT
• Explain how research involving humans or animals is regulated
Scientific research is a critical tool for successfully navigating our complex world. Without it, we would be forced to
rely solely on intuition, other people’s authority, and blind luck. While many of us feel confident in our abilities to
decipher and interact with the world around us, history is filled with examples of how very wrong we can be when
we fail to recognize the need for evidence in supporting claims. At various times in history, we would have been
certain that the sun revolved around a flat earth, that the earth’s continents did not move, and that mental illness
was caused by possession (Figure 1). It is through systematic scientific research that we divest ourselves of our
preconceived notions and superstitions and gain an objective understanding of ourselves and our world.
The goal of all scientists is to better understand the world
around them. Psychologists focus their attention on
understanding behavior, as well as the cognitive (mental)
and physiological (body) processes that underlie behavior.
In contrast to other methods that people use to understand
the behavior of others, such as intuition and personal
experience, the hallmark of scientific research is that there
is evidence to support a claim. Scientific knowledge is
empirical: It is grounded in objective, tangible evidence that
can be observed time and time again, regardless of who is
observing.
While behavior is observable, the mind is not. If someone is
crying, we can see behavior. However, the reason for the
behavior is more difficult to determine. Is the person crying
due to being sad, in pain, or happy? Sometimes we can
learn the reason for someone’s behavior by simply asking a
question, like “Why are you crying?” However, there are
situations in which an individual is either uncomfortable or
unwilling to answer the question honestly, or is incapable of
answering. For example, infants would not be able to
explain why they are crying. In such circumstances, the
psychologist must be creative in finding ways to better
understand behavior. This module explores how scientific knowledge is generated, and how important that
knowledge is in forming decisions in our personal lives and in the public domain.

Figure 2. The scientific method is a process for gathering
data and processing information. It provides well-defined
steps to standardize how scientific knowledge is gathered
through a logical, rational problem-solving method.
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The Process of Scientific Research
Scientific knowledge is advanced through a process known
as the scientific method. Basically, ideas (in the form of
theories and hypotheses) are tested against the real world
(in the form of empiricalempirical observations), and those empirical
observations lead to more ideas that are tested against the
real world, and so on.
The basic steps in the scientific method are:
• Observe a natural phenomenon and define a
question about it
• Make a hypothesis, or potential solution to the
question
• Test the hypothesis
• If the hypothesis is true, find more evidence or find
counter-evidence
• If the hypothesis is false, create a new hypothesis
or try again
• Draw conclusions and repeat–the scientific
method is never-ending, and no result is ever
considered perfect
In order to ask an important question that may improve our
understanding of the world, a researcher must first observe
natural phenomena. By making observations, a researcher
can define a useful question. After finding a question to
answer, the researcher can then make a prediction (a
hypothesis) about what he or she thinks the answer will be.
This prediction is usually a statement about the relationship
between two or more variables. After making a hypothesis,
the researcher will then design an experiment to test his or
her hypothesis and evaluate the data gathered. These data
will either support or refute the hypothesis. Based on the
conclusions drawn from the data, the researcher will then
find more evidence to support the hypothesis, look for
counter-evidence to further strengthen the hypothesis,
revise the hypothesis and create a new experiment, or
continue to incorporate the information gathered to answer
the research question.
The Basic Principles of the Scientific
Method
Two key concepts in the scientific approach are theory and hypothesis. A theorytheory is a well-developed set of ideas
that propose an explanation for observed phenomena that can be used to make predictions about future
observations. A hypothesishypothesis is a testable prediction that is arrived at logically from a theory. It is often worded as
an if-then statement (e.g., if I study all night, I will get a passing grade on the test). The hypothesis is extremely
important because it bridges the gap between the realm of ideas and the real world. As specific hypotheses are
tested, theories are modified and refined to reflect and incorporate the result of these tests (Figure 2).

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Figure 3. The scientific method of research includes
proposing hypotheses, conducting research, and creating
or modifying theories based on results.
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Other key components in following the scientific method
include verifiability, predictability, falsifiability, and fairness.
VerifiabilityVerifiability means that an experiment must be replicable by
another researcher. To achieve verifiability, researchers
must make sure to document their methods and clearly
explain how their experiment is structured and why it
produces certain results.
PredictabilityPredictability in a scientific theory implies that the theory
should enable us to make predictions about future events.
The precision of these predictions is a measure of the
strength of the theory.
FalsifiabilityFalsifiability refers to whether a hypothesis can disproved.
For a hypothesis to be falsifiable, it must be logically
possible to make an observation or do a physical
experiment that would show that there is no support for the
hypothesis. Even when a hypothesis cannot be shown to be
false, that does not necessarily mean it is not valid. Future
testing may disprove the hypothesis. This does not mean
that a hypothesis has to be shown to be false, just that it
can be tested.
To determine whether a hypothesis is supported or not supported, psychological researchers must conduct
hypothesis testing using statistics. Hypothesis testing is a type of statistics that determines the probability of a
hypothesis being true or false. If hypothesis testing reveals that results were “statistically significant,” this
means that there was support for the hypothesis and that the researchers can be reasonably confident that their
result was not due to random chance. If the results are not statistically significant, this means that the
researchers’ hypothesis was not supported.
FairnessFairness implies that all data must be considered when evaluating a hypothesis. A researcher cannot pick and
choose what data to keep and what to discard or focus specifically on data that support or do not support a
particular hypothesis. All data must be accounted for, even if they invalidate the hypothesis.

Applying the Scientific Method
To see how this process works, let’s consider a specific theory and a hypothesis that might be generated from
that theory. As you’ll learn in a later module, the James-Lange theory of emotion asserts that emotional
experience relies on the physiological arousal associated with the emotional state. If you walked out of your home
and discovered a very aggressive snake waiting on your doorstep, your heart would begin to race and your
stomach churn. According to the James-Lange theory, these physiological changes would result in your feeling of
fear. A hypothesis that could be derived from this theory might be that a person who is unaware of the
physiological arousal that the sight of the snake elicits will not feel fear.
Remember that a good scientific hypothesis is falsifiable, or capable of being shown to be incorrect. Recall from
the introductory module that Sigmund Freud had lots of interesting ideas to explain various human behaviors
(Figure 3). However, a major criticism of Freud’s theories is that many of his ideas are not falsifiable; for example,
it is impossible to imagine empirical observations that would disprove the existence of the id, the ego, and the
superego—the three elements of personality described in Freud’s theories. Despite this, Freud’s theories are
widely taught in introductory psychology texts because of their historical significance for personality psychology
and psychotherapy, and these remain the root of all modern forms of therapy.
Figure 4. Many of the specifics of (a) Freud’s theories, such as (b) his division of the mind into id, ego, and superego, have fallen
out of favor in recent decades because they are not falsifiable. In broader strokes, his views set the stage for much of
psychological thinking today, such as the unconscious nature of the majority of psychological processes.
In contrast, the James-Lange theory does generate falsifiable hypotheses, such as the one described above.
Some individuals who suffer significant injuries to their spinal columns are unable to feel the bodily changes that
often accompany emotional experiences. Therefore, we could test the hypothesis by determining how emotional
experiences differ between individuals who have the ability to detect these changes in their physiological arousal
and those who do not. In fact, this research has been conducted and while the emotional experiences of people
deprived of an awareness of their physiological arousal may be less intense, they still experience emotion
(Chwalisz, Diener, & Gallagher, 1988).

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LINK TO LEARNINGLINK TO LEARNING
Want to participate in a study? Visit this website and click on a link that sounds interesting to you in order to
participate in online research.
LINK TO LEARNINGLINK TO LEARNING
Visit this website to apply the scientific method and practice its steps by using them to solve a murder mystery,
determine why a student is in trouble, and design an experiment to test house paint.
Why the Scientific Method Is Important for Psychology
The use of the scientific method is one of the main features that separates modern psychology from earlier
philosophical inquiries about the mind. Compared to chemistry, physics, and other “natural sciences,” psychology
has long been considered one of the “social sciences” because of the subjective nature of the things it seeks to
study. Many of the concepts that psychologists are interested in—such as aspects of the human mind, behavior,
and emotions—are subjective and cannot be directly measured. Psychologists often rely instead on behavioral
observations and self-reported data, which are considered by some to be illegitimate or lacking in methodological
rigor. Applying the scientific method to psychology, therefore, helps to standardize the approach to understanding
its very different types of information.
The scientific method allows psychological data to be replicated and confirmed in many instances, under different
circumstances, and by a variety of researchers. Through replication of experiments, new generations of
psychologists can reduce errors and broaden the applicability of theories. It also allows theories to be tested and
validated instead of simply being conjectures that could never be verified or falsified. All of this allows
psychologists to gain a stronger understanding of how the human mind works.
Scientific articles published in journals and psychology papers written in the style of the American Psychological
Association (i.e., in “APA style”) are structured around the scientific method. These papers include an
Introduction, which introduces the background information and outlines the hypotheses; a Methods section, which
outlines the specifics of how the experiment was conducted to test the hypothesis; a Results section, which
includes the statistics that tested the hypothesis and state whether it was supported or not supported, and a
Discussion and Conclusion, which state the implications of finding support for, or no support for, the hypothesis.
Writing articles and papers that adhere to the scientific method makes it easy for future researchers to repeat the
study and attempt to replicate the results.
Today, scientists agree that good research is ethical in nature and is guided by a basic respect for human dignity
and safety. However, as you will read in the Tuskegee Syphilis Study, this has not always been the case. Modern

http://psych.hanover.edu/Research/exponnet.html#Relationships

http://aspire.cosmic-ray.org/Labs/ScientificMethod/sci_method_selector.swf

Figure 1. An institution’s IRB meets regularly to review
experimental proposals that involve human participants.
(credit: modification of work by Lowndes Area Knowledge
Exchange (LAKE)/Flickr)
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researchers must demonstrate that the research they perform is ethically sound. This section presents how
ethical considerations affect the design and implementation of research conducted today.
Research Involving Human Participants
Any experiment involving the participation of human subjects is governed by extensive, strict guidelines designed
to ensure that the experiment does not result in harm. Any research institution that receives federal support for
research involving human participants must have access to an institutional review board (IRB)institutional review board (IRB). The IRB is a
committee of individuals often made up of members of the institution’s administration, scientists, and community
members (Figure 1). The purpose of the IRB is to review proposals for research that involves human participants.
The IRB reviews these proposals with the principles mentioned above in mind, and generally, approval from the
IRB is required in order for the experiment to proceed.
An institution’s IRB requires several components in any
experiment it approves. For one, each participant must sign
an informed consent form before they can participate in the
experiment. An informed consentinformed consent form provides a written
description of what participants can expect during the
experiment, including potential risks and implications of the
research. It also lets participants know that their
involvement is completely voluntary and can be
discontinued without penalty at any time. Furthermore, the
informed consent guarantees that any data collected in the
experiment will remain completely confidential. In cases
where research participants are under the age of 18, the
parents or legal guardians are required to sign the informed
consent form.
While the informed consent form should be as honest as
possible in describing exactly what participants will be
doing, sometimes deception is necessary to prevent
participants’ knowledge of the exact research question from
affecting the results of the study. DeceptionDeception involves
purposely misleading experiment participants in order to
maintain the integrity of the experiment, but not to the point
where the deception could be considered harmful. For example, if we are interested in how our opinion of
someone is affected by their attire, we might use deception in describing the experiment to prevent that
knowledge from affecting participants’ responses. In cases where deception is involved, participants must receive
a full debriefingdebriefing upon conclusion of the study—complete, honest information about the purpose of the experiment,
how the data collected will be used, the reasons why deception was necessary, and information about how to
obtain additional information about the study.

Figure 2. A participant in the Tuskegee Syphilis Study receives an injection.
DIG DEEPER: ETHICS AND THE TUSKEGEE SYPHILIS STUDYDIG DEEPER: ETHICS AND THE TUSKEGEE SYPHILIS STUDY
Unfortunately, the ethical guidelines that exist for research today were not always applied in the past. In 1932,
poor, rural, black, male sharecroppers from Tuskegee, Alabama, were recruited to participate in an experiment
conducted by the U.S. Public Health Service, with the aim of studying syphilis in black men (Figure 2). In
exchange for free medical care, meals, and burial insurance, 600 men agreed to participate in the study. A little
more than half of the men tested positive for syphilis, and they served as the experimental group (given that the
researchers could not randomly assign participants to groups, this represents a quasi-experiment). The
remaining syphilis-free individuals served as the control group. However, those individuals that tested positive
for syphilis were never informed that they had the disease.
While there was no treatment for syphilis when the study began, by 1947 penicillin was recognized as an
effective treatment for the disease. Despite this, no penicillin was administered to the participants in this study,
and the participants were not allowed to seek treatment at any other facilities if they continued in the study.
Over the course of 40 years, many of the participants unknowingly spread syphilis to their wives (and
subsequently their children born from their wives) and eventually died because they never received treatment
for the disease. This study was discontinued in 1972 when the experiment was discovered by the national
press (Tuskegee University, n.d.). The resulting outrage over the experiment led directly to the National
Research Act of 1974 and the strict ethical guidelines for research on humans described in this chapter. Why is
this study unethical? How were the men who participated and their families harmed as a function of this
research?
Visit this website to learn more about the Tuskegee Syphilis Study.

http://www.tuskegee.edu/about_us/centers_of_excellence/bioethics_center/about_the_usphs_syphilis_study.aspx

Figure 3. Rats, like the one shown here, often serve as
the subjects of animal research.
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GLOSSARYGLOSSARY
debriefing:debriefing: when an experiment involved deception, participants are told complete and truthful information
about the experiment at its conclusion
Research Involving Animal Subjects
Many psychologists conduct research involving animal subjects. Often, these researchers use rodents (Figure 3)
or birds as the subjects of their experiments—the APA estimates that 90% of all animal research in psychology
uses these species (American Psychological Association, n.d.). Because many basic processes in animals are
sufficiently similar to those in humans, these animals are acceptable substitutes for research that would be
considered unethical in human participants.
This does not mean that animal researchers are immune to
ethical concerns. Indeed, the humane and ethical treatment
of animal research subjects is a critical aspect of this type
of research. Researchers must design their experiments to
minimize any pain or distress experienced by animals
serving as research subjects.
Whereas IRBs review research proposals that involve
human participants, animal experimental proposals are
reviewed by an Institutional Animal Care and UseInstitutional Animal Care and Use
Committee (IACUC)Committee (IACUC). An IACUC consists of institutional
administrators, scientists, veterinarians, and community
members. This committee is charged with ensuring that all
experimental proposals require the humane treatment of
animal research subjects. It also conducts semi-annual
inspections of all animal facilities to ensure that the
research protocols are being followed. No animal research
project can proceed without the committee’s approval.

deception:deception: purposely misleading experiment participants in order to maintain the integrity of the experiment
empirical:empirical: grounded in objective, tangible evidence that can be observed time and time again, regardless of
who is observing
fairness:fairness: implies that all data must be considered when evaluating a hypothesis
falsifiable:falsifiable: able to be disproven by experimental results
hypothesis:hypothesis: (plural: hypotheses) tentative and testable statement about the relationship between two or more
variables
informed consent:informed consent: process of informing a research participant about what to expect during an experiment, any
risks involved, and the implications of the research, and then obtaining the person’s consent to participate
Institutional Animal Care and Use Committee (IACUC):Institutional Animal Care and Use Committee (IACUC): committee of administrators, scientists, and community
members that reviews proposals for research involving animal participants
Institutional Review Board (IRB):Institutional Review Board (IRB): committee of administrators, scientists, veterinarians, and community
members that reviews proposals for research involving human participants
predictability:predictability: implies that a theory should enable us to make predictions about future events
theory:theory: well-developed set of ideas that propose an explanation for observed phenomena
verifiability:verifiability: an experiment must be replicable by another researcher
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DESCRIPTIVE RESEARCH
What you’ll learn to do: describe the strengths and weaknesses of
descriptive, experimental, and correlational research
If you think about the vast array of fields and topics covered in psychology, you understand that in order to do
psychological research, there must be a diverse set of ways to gather data and perform experiments. For
example, a biological psychologist might work predominately in a lab setting or alongside a neurologist. A social
scientist may set up situational experiments, a health psychologist may administer surveys, and a developmental
psychologist may make observations in a classroom. In this section, you’ll learn about the various types of
research methods that psychologists employ to learn about human behavior.
Psychologists use descriptive, experimental, and correlational methods to conduct research. Descriptive, or
qualitative, methods include the case study, naturalistic observation, surveys, archival research, longitudinal
research, and cross-sectional research.
Experiments are conducted in order to determine cause-and-effect relationships. In ideal experimental design, the
only difference between the experimental and control groups is whether participants are exposed to the
experimental manipulation. Each group goes through all phases of the experiment, but each group will experience
a different level of the independent variable: the experimental group is exposed to the experimental manipulation,
and the control group is not exposed to the experimental manipulation. The researcher then measures the
changes that are produced in the dependent variable in each group. Once data is collected from both groups, it is
analyzed statistically to determine if there are meaningful differences between the groups.
When scientists passively observe and measure phenomena it is called correlational research. Here,
psychologists do not intervene and change behavior, as they do in experiments. In correlational research, they
identify patterns of relationships, but usually cannot infer what causes what. Importantly, with correlational
research, you can examine only two variables at a time, no more and no less.

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MORE ON RESEARCHMORE ON RESEARCH
If you enjoy learning through lectures and want an interesting and comprehensive summary of this section,
then click on the link HERE (or on the link below) to watch a lecture given by MIT Professor John Gabrieli. StartStart
at the 30:45 minute markat the 30:45 minute mark and watch through the end to hear examples of actual psychological studies and how
they were analyzed. Listen for references to independent and dependent variables, experimenter bias, and
double-blind studies. In the lecture, you’ll learn about breaking social norms, “WEIRD” research, why
expectations matter, how a warm cup of coffee might make you nicer, why you should change your answer on
a multiple choice test, and why praise for intelligence won’t make you any smarter.
LEARNING OBJECTIVESLEARNING OBJECTIVES
• Differentiate between descriptive, experimental, and correlational research
• Explain the strengths and weaknesses of case studies, naturalistic observation, and surveys
• Describe the strength and weaknesses of archival research
• Compare longitudinal and cross-sectional approaches to research
Descriptive Research
There are many research methods available to psychologists in their efforts to understand, describe, and explain
behavior and the cognitive and biological processes that underlie it. Some methods rely on observational
techniques. Other approaches involve interactions between the researcher and the individuals who are being

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studied—ranging from a series of simple questions to extensive, in-depth interviews—to well-controlled
experiments.
The three main categories of psychological research are descriptive, correlational, and experimental
research. Research studies that do not test specific relationships between variables are called descriptive, ordescriptive, or
qualitative, studiesqualitative, studies. These studies are used to describe general or specific behaviors and attributes that are
observed and measured. In the early stages of research it might be difficult to form a hypothesis, especially when
there is not any existing literature in the area. In these situations designing an experiment would be premature, as
the question of interest is not yet clearly defined as a hypothesis. Often a researcher will begin with a non-
experimental approach, such as a descriptive study, to gather more information about the topic before designing
an experiment or correlational study to address a specific hypothesis. Descriptive research is distinct from
correlational researchcorrelational research, in which psychologists formally test whether a relationship exists between two or more
variables. Experimental researchExperimental research goes a step further beyond descriptive and correlational research and randomly
assigns people to different conditions, using hypothesis testing to make inferences about how these conditions
affect behavior. It aims to determine if one variable directly impacts and causes another. Correlational and
experimental research both typically use hypothesis testing, whereas descriptive research does not.
Each of these research methods has unique strengths and weaknesses, and each method may only be
appropriate for certain types of research questions. For example, studies that rely primarily on observation
produce incredible amounts of information, but the ability to apply this information to the larger population is
somewhat limited because of small sample sizes. Survey research, on the other hand, allows researchers to
easily collect data from relatively large samples. While this allows for results to be generalized to the larger
population more easily, the information that can be collected on any given survey is somewhat limited and subject
to problems associated with any type of self-reported data. Some researchers conduct archival research by using
existing records. While this can be a fairly inexpensive way to collect data that can provide insight into a number
of research questions, researchers using this approach have no control on how or what kind of data was
collected.
Correlational research can find a relationship between two variables, but the only way a researcher can claim that
the relationship between the variables is cause and effect is to perform an experiment. In experimental research,
which will be discussed later in the text, there is a tremendous amount of control over variables of interest. While
this is a powerful approach, experiments are often conducted in very artificial settings. This calls into question the
validity of experimental findings with regard to how they would apply in real-world settings. In addition, many of
the questions that psychologists would like to answer cannot be pursued through experimental research because
of ethical concerns.
The three main types of descriptive studies are case studies, naturalistic observation, and surveys.

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LINK TO LEARNINGLINK TO LEARNING
To learn more about Krista and Tatiana, watch this New York Times video about their lives.
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Case Studies
In 2011, the New York Times published a feature story on Krista and Tatiana Hogan, Canadian twin girls. These
particular twins are unique because Krista and Tatiana are conjoined twins, connected at the head. There is
evidence that the two girls are connected in a part of the brain called the thalamus, which is a major sensory relay
center. Most incoming sensory information is sent through the thalamus before reaching higher regions of the
cerebral cortex for processing.
The implications of this potential connection mean that it might be possible for one twin to experience the
sensations of the other twin. For instance, if Krista is watching a particularly funny television program, Tatiana
might smile or laugh even if she is not watching the program. This particular possibility has piqued the interest of
many neuroscientists who seek to understand how the brain uses sensory information.
These twins represent an enormous resource in the study of the brain, and since their condition is very rare, it is
likely that as long as their family agrees, scientists will follow these girls very closely throughout their lives to gain
as much information as possible (Dominus, 2011).
In observational research, scientists are conducting a clinical or case studycase study when they focus on one person or just
a few individuals. Indeed, some scientists spend their entire careers studying just 10–20 individuals. Why would
they do this? Obviously, when they focus their attention on a very small number of people, they can gain a
tremendous amount of insight into those cases. The richness of information that is collected in clinical or case
studies is unmatched by any other single research method. This allows the researcher to have a very deep
understanding of the individuals and the particular phenomenon being studied.
If clinical or case studies provide so much information, why are they not more frequent among researchers? As it
turns out, the major benefit of this particular approach is also a weakness. As mentioned earlier, this approach is
often used when studying individuals who are interesting to researchers because they have a rare characteristic.
Therefore, the individuals who serve as the focus of case studies are not like most other people. If scientists
ultimately want to explain all behavior, focusing attention on such a special group of people can make it difficult to
generalize any observations to the larger population as a whole. Generalizing refers to the ability to apply the
findings of a particular research project to larger segments of society. Again, case studies provide enormous
amounts of information, but since the cases are so specific, the potential to apply what’s learned to the average
person may be very limited.

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Figure 1. Seeing a police car behind you would probably
affect your driving behavior. (credit: Michael Gil)
Naturalistic Observation
If you want to understand how behavior occurs, one of the best ways to gain information is to simply observe the
behavior in its natural context. However, people might change their behavior in unexpected ways if they know
they are being observed. How do researchers obtain accurate information when people tend to hide their natural
behavior? As an example, imagine that your professor asks everyone in your class to raise their hand if they
always wash their hands after using the restroom. Chances are that almost everyone in the classroom will raise
their hand, but do you think hand washing after every trip to the restroom is really that universal?
This is very similar to the phenomenon mentioned earlier in this chapter: many individuals do not feel comfortable
answering a question honestly. But if we are committed to finding out the facts about hand washing, we have
other options available to us.
Suppose we send a classmate into the restroom to actually watch whether everyone washes their hands after
using the restroom. Will our observer blend into the restroom environment by wearing a white lab coat, sitting with
a clipboard, and staring at the sinks? We want our researcher to be inconspicuous—perhaps standing at one of
the sinks pretending to put in contact lenses while secretly recording the relevant information. This type of
observational study is called naturalistic observationnaturalistic observation: observing behavior in its natural setting. To better
understand peer exclusion, Suzanne Fanger collaborated with colleagues at the University of Texas to observe
the behavior of preschool children on a playground. How did the observers remain inconspicuous over the
duration of the study? They equipped a few of the children with wireless microphones (which the children quickly
forgot about) and observed while taking notes from a distance. Also, the children in that particular preschool (a
“laboratory preschool”) were accustomed to having observers on the playground (Fanger, Frankel, & Hazen,
2012).
It is critical that the observer be as unobtrusive and as
inconspicuous as possible: when people know they are
being watched, they are less likely to behave naturally. If
you have any doubt about this, ask yourself how your
driving behavior might differ in two situations: In the first
situation, you are driving down a deserted highway during
the middle of the day; in the second situation, you are being
followed by a police car down the same deserted highway
(Figure 1).
It should be pointed out that naturalistic observation is not
limited to research involving humans. Indeed, some of the
best-known examples of naturalistic observation involve
researchers going into the field to observe various kinds of
animals in their own environments. As with human studies,
the researchers maintain their distance and avoid
interfering with the animal subjects so as not to influence
their natural behaviors. Scientists have used this technique
to study social hierarchies and interactions among animals
ranging from ground squirrels to gorillas. The information provided by these studies is invaluable in understanding
how those animals organize socially and communicate with one another. The anthropologist Jane Goodall, for
example, spent nearly five decades observing the behavior of chimpanzees in Africa (Figure 2). As an illustration
of the types of concerns that a researcher might encounter in naturalistic observation, some scientists criticized
Goodall for giving the chimps names instead of referring to them by numbers—using names was thought to
undermine the emotional detachment required for the objectivity of the study (McKie, 2010).

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Figure 2. (a) Jane Goodall made a career of conducting naturalistic observations of (b) chimpanzee behavior. (credit “Jane
Goodall”: modification of work by Erik Hersman; “chimpanzee”: modification of work by “Afrika Force”/Flickr.com)
The greatest benefit of naturalistic observation is the validity, or accuracy, of information collected unobtrusively in
a natural setting. Having individuals behave as they normally would in a given situation means that we have a
higher degree of ecological validity, or realism, than we might achieve with other research approaches. Therefore,
our ability to generalizegeneralize the findings of the research to real-world situations is enhanced. If done correctly, we
need not worry about people or animals modifying their behavior simply because they are being observed.
Sometimes, people may assume that reality programs give us a glimpse into authentic human behavior. However,
the principle of inconspicuous observation is violated as reality stars are followed by camera crews and are
interviewed on camera for personal confessionals. Given that environment, we must doubt how natural and
realistic their behaviors are.
The major downside of naturalistic observation is that they are often difficult to set up and control. In our restroom
study, what if you stood in the restroom all day prepared to record people’s hand washing behavior and no one
came in? Or, what if you have been closely observing a troop of gorillas for weeks only to find that they migrated
to a new place while you were sleeping in your tent? The benefit of realistic data comes at a cost. As a researcher
you have no control of when (or if) you have behavior to observe. In addition, this type of observational research
often requires significant investments of time, money, and a good dose of luck.
Sometimes studies involve structured observation. In these cases, people are observed while engaging in set,
specific tasks. An excellent example of structured observation comes from Strange Situation by Mary Ainsworth
(you will read more about this in the chapter on lifespan development). The Strange Situation is a procedure used
to evaluate attachment styles that exist between an infant and caregiver. In this scenario, caregivers bring their
infants into a room filled with toys. The Strange Situation involves a number of phases, including a stranger
coming into the room, the caregiver leaving the room, and the caregiver’s return to the room. The infant’s
behavior is closely monitored at each phase, but it is the behavior of the infant upon being reunited with the
caregiver that is most telling in terms of characterizing the infant’s attachment style with the caregiver.
Another potential problem in observational research is observer biasobserver bias. Generally, people who act as observers are
closely involved in the research project and may unconsciously skew their observations to fit their research goals
or expectations. To protect against this type of bias, researchers should have clear criteria established for the
types of behaviors recorded and how those behaviors should be classified. In addition, researchers often
compare observations of the same event by multiple observers, in order to test inter-rater reliabilityinter-rater reliability: a measure of
reliability that assesses the consistency of observations by different observers.

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Figure 3. Surveys can be administered in a number of
ways, including electronically administered research, like
the survey shown here. (credit: Robert Nyman)
Surveys
Often, psychologists develop surveys as a means of gathering data. SurveysSurveys are lists of questions to be
answered by research participants, and can be delivered as paper-and-pencil questionnaires, administered
electronically, or conducted verbally (Figure 3). Generally, the survey itself can be completed in a short time, and
the ease of administering a survey makes it easy to collect data from a large number of people.
Surveys allow researchers to gather data from larger samples than may be afforded by other research methods..
A samplesample is a subset of individuals selected from a populationpopulation, which is the overall group of individuals that the
researchers are interested in. Researchers study the sample and seek to generalize their findings to the
population.
There is both strength and weakness of the survey in
comparison to case studies. By using surveys, we can
collect information from a larger sample of people. A larger
sample is better able to reflect the actual diversity of the
population, thus allowing better generalizability. Therefore,
if our sample is sufficiently large and diverse, we can
assume that the data we collect from the survey can be
generalized to the larger population with more certainty
than the information collected through a case study.
However, given the greater number of people involved, we
are not able to collect the same depth of information on
each person that would be collected in a case study.
Another potential weakness of surveys is something we
touched on earlier in this chapter: People don’t always give
accurate responses. They may lie, misremember, or
answer questions in a way that they think makes them look
good. For example, people may report drinking less alcohol
than is actually the case.
Any number of research questions can be answered through the use of surveys. One real-world example is the
research conducted by Jenkins, Ruppel, Kizer, Yehl, and Griffin (2012) about the backlash against the US Arab-
American community following the terrorist attacks of September 11, 2001. Jenkins and colleagues wanted to
determine to what extent these negative attitudes toward Arab-Americans still existed nearly a decade after the
attacks occurred. In one study, 140 research participants filled out a survey with 10 questions, including questions
asking directly about the participant’s overt prejudicial attitudes toward people of various ethnicities. The survey
also asked indirect questions about how likely the participant would be to interact with a person of a given
ethnicity in a variety of settings (such as, “How likely do you think it is that you would introduce yourself to a
person of Arab-American descent?”). The results of the research suggested that participants were unwilling to
report prejudicial attitudes toward any ethnic group. However, there were significant differences between their
pattern of responses to questions about social interaction with Arab-Americans compared to other ethnic groups:
they indicated less willingness for social interaction with Arab-Americans compared to the other ethnic groups.
This suggested that the participants harbored subtle forms of prejudice against Arab-Americans, despite their
assertions that this was not the case (Jenkins et al., 2012).

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THINK IT OVERTHINK IT OVER
A friend of yours is working part-time in a local pet store. Your friend has become increasingly interested in how
dogs normally communicate and interact with each other, and is thinking of visiting a local veterinary clinic to
see how dogs interact in the waiting room. After reading this section, do you think this is the best way to better
understand such interactions? Do you have any suggestions that might result in more valid data?
Archival Research
Some researchers gain access to large amounts of data without interacting with a single research participant.
Instead, they use existing records to answer various research questions. This type of research approach is known
as archival research. Archival researchArchival research relies on looking at past records or data sets to look for interesting
patterns or relationships.
For example, a researcher might access the academic records of all individuals who enrolled in college within the
past ten years and calculate how long it took them to complete their degrees, as well as course loads, grades,
and extracurricular involvement. Archival research could provide important information about who is most likely to
complete their education, and it could help identify important risk factors for struggling students (Figure 1).

Figure 1. A researcher doing archival research examines records, whether archived as a (a) hardcopy or (b) electronically. (credit
“paper files”: modification of work by “Newtown graffiti”/Flickr; “computer”: modification of work by INPIVIC Family/Flickr)
In comparing archival research to other research methods, there are several important distinctions. For one, the
researcher employing archival research never directly interacts with research participants. Therefore, the
investment of time and money to collect data is considerably less with archival research. Additionally, researchers
have no control over what information was originally collected. Therefore, research questions have to be tailored
so they can be answered within the structure of the existing data sets. There is also no guarantee of consistency
between the records from one source to another, which might make comparing and contrasting different data sets
problematic.
Longitudinal and Cross-Sectional Research
Sometimes we want to see how people change over time, as in studies of human development and lifespan.
When we test the same group of individuals repeatedly over an extended period of time, we are conducting
longitudinal research. LongitudinalLongitudinal research is a research design in which data-gathering is administered
repeatedly over an extended period of time. For example, we may survey a group of individuals about their dietary
habits at age 20, retest them a decade later at age 30, and then again at age 40.
Another approach is cross-sectionalcross-sectional research. In cross-sectional research, a researcher compares multiple
segments of the population at the same time. Using the dietary habits example above, the researcher might
directly compare different groups of people by age. Instead a group of people for 20 years to see how their dietary
habits changed from decade to decade, the researcher would study a group of 20-year-old individuals and
compare them to a group of 30-year-old individuals and a group of 40-year-old individuals. While cross-sectional
research requires a shorter-term investment, it is also limited by differences that exist between the different
generations (or cohorts) that have nothing to do with age per se, but rather reflect the social and cultural
experiences of different generations of individuals make them different from one another.
To illustrate this concept, consider the following survey findings. In recent years there has been significant growth
in the popular support of same-sex marriage. Many studies on this topic break down survey participants into
different age groups. In general, younger people are more supportive of same-sex marriage than are those who
are older (Jones, 2013). Does this mean that as we age we become less open to the idea of same-sex marriage,
or does this mean that older individuals have different perspectives because of the social climates in which they
grew up? Longitudinal research is a powerful approach because the same individuals are involved in the research
project over time, which means that the researchers need to be less concerned with differences among cohorts
affecting the results of their study.
Often longitudinal studies are employed when researching various diseases in an effort to understand particular
risk factors. Such studies often involve tens of thousands of individuals who are followed for several decades.
Given the enormous number of people involved in these studies, researchers can feel confident that their findings
can be generalized to the larger population. The Cancer Prevention Study-3 (CPS-3) is one of a series of

Figure 2. Longitudinal research like the CPS-3 help us to
better understand how smoking is associated with cancer
and other diseases. (credit: CDC/Debora Cartagena)
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longitudinal studies sponsored by the American Cancer Society aimed at determining predictive risk factors
associated with cancer. When participants enter the study, they complete a survey about their lives and family
histories, providing information on factors that might cause or prevent the development of cancer. Then every few
years the participants receive additional surveys to complete. In the end, hundreds of thousands of participants
will be tracked over 20 years to determine which of them develop cancer and which do not.
Clearly, this type of research is important and potentially very informative. For instance, earlier longitudinal studies
sponsored by the American Cancer Society provided some of the first scientific demonstrations of the now well-
established links between increased rates of cancer and smoking (American Cancer Society, n.d.) (Figure 2).
As with any research strategy, longitudinal research is not
without limitations. For one, these studies require an
incredible time investment by the researcher and research
participants. Given that some longitudinal studies take
years, if not decades, to complete, the results will not be
known for a considerable period of time. In addition to the
time demands, these studies also require a substantial
financial investment. Many researchers are unable to
commit the resources necessary to see a longitudinal
project through to the end.
Research participants must also be willing to continue their
participation for an extended period of time, and this can be
problematic. People move, get married and take new
names, get ill, and eventually die. Even without significant
life changes, some people may simply choose to
discontinue their participation in the project. As a result, the
attritionattrition rates, or reduction in the number of research
participants due to dropouts, in longitudinal studies are quite high and increases over the course of a project. For
this reason, researchers using this approach typically recruit many participants fully expecting that a substantial
number will drop out before the end. As the study progresses, they continually check whether the sample still
represents the larger population, and make adjustments as necessary.

GLOSSARYGLOSSARY
archival research:archival research: method of research using past records or data sets to answer various research questions, or
to search for interesting patterns or relationships
attrition:attrition: reduction in number of research participants as some drop out of the study over time
clinical or case study:clinical or case study: observational research study focusing on one or a few people
correlational research:correlational research: tests whether a relationship exists between two or more variables
cross-sectional research:cross-sectional research: compares multiple segments of a population at a single time
descriptive research:descriptive research: research studies that do not test specific relationships between variables; they are used to
describe general or specific behaviors and attributes that are observed and measured
experimental research:experimental research: tests a hypothesis to determine cause and effect relationships
generalizegeneralize inferring that the results for a sample apply to the larger population
inter-rater reliability:inter-rater reliability: measure of agreement among observers on how they record and classify a particular event
longitudinal research:longitudinal research: studies in which the same group of individuals is surveyed or measured repeatedly over
an extended period of time
naturalistic observation:naturalistic observation: observation of behavior in its natural setting
observer bias:observer bias: when observations may be skewed to align with observer expectations
population:population: overall group of individuals that the researchers are interested in
sample:sample: subset of individuals selected from the larger population
survey:survey: list of questions to be answered by research participants—given as paper-and-pencil questionnaires,
administered electronically, or conducted verbally—allowing researchers to collect data from a large number of
people
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CORRELATIONAL RESEARCH
LEARNING OBJECTIVESLEARNING OBJECTIVES
• Explain what a correlation coefficient tells us about the relationship between variables
• Describe why correlation does not mean causation
Did you know that as sales in ice cream increase, so does the overall rate of crime? Is it possible that indulging in
your favorite flavor of ice cream could send you on a crime spree? Or, after committing crime do you think you
might decide to treat yourself to a cone? There is no question that a relationship exists between ice cream and

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crime (e.g., Harper, 2013), but it would be pretty foolish to decide that one thing actually caused the other to
occur.
It is much more likely that both ice cream sales and crime rates are related to the temperature outside. When the
temperature is warm, there are lots of people out of their houses, interacting with each other, getting annoyed with
one another, and sometimes committing crimes. Also, when it is warm outside, we are more likely to seek a cool
treat like ice cream. How do we determine if there is indeed a relationship between two things? And when there is
a relationship, how can we discern whether it is attributable to coincidence or causation?
Correlational Research
CorrelationCorrelation means that there is a relationship between two or more variables (such as ice cream consumption and
crime), but this relationship does not necessarily imply cause and effect. When two variables are correlated, it
simply means that as one variable changes, so does the other. We can measure correlation by calculating a
statistic known as a correlation coefficient. A correlation coefficientcorrelation coefficient is a number from -1 to +1 that indicates the
strength and direction of the relationship between variables. The correlation coefficient is usually represented by
the letter r.
The number portion of the correlation coefficient indicates the strength of the relationship. The closer the number
is to 1 (be it negative or positive), the more strongly related the variables are, and the more predictable changes
in one variable will be as the other variable changes. The closer the number is to zero, the weaker the
relationship, and the less predictable the relationships between the variables becomes. For instance, a correlation
coefficient of 0.9 indicates a far stronger relationship than a correlation coefficient of 0.3. If the variables are not
related to one another at all, the correlation coefficient is 0. The example above about ice cream and crime is an
example of two variables that we might expect to have no relationship to each other.
The sign—positive or negative—of the correlation coefficient indicates the direction of the relationship (Figure 1).
A positive correlationpositive correlation means that the variables move in the same direction. Put another way, it means that as one
variable increases so does the other, and conversely, when one variable decreases so does the other. A negativenegative
correlationcorrelation means that the variables move in opposite directions. If two variables are negatively correlated, a
decrease in one variable is associated with an increase in the other and vice versa.
The example of ice cream and crime rates is a positive correlation because both variables increase when
temperatures are warmer. Other examples of positive correlations are the relationship between an individual’s
height and weight or the relationship between a person’s age and number of wrinkles. One might expect a
negative correlation to exist between someone’s tiredness during the day and the number of hours they slept the
previous night: the amount of sleep decreases as the feelings of tiredness increase. In a real-world example of
negative correlation, student researchers at the University of Minnesota found a weak negative correlation (r =
-0.29) between the average number of days per week that students got fewer than 5 hours of sleep and their GPA
(Lowry, Dean, & Manders, 2010). Keep in mind that a negative correlation is not the same as no correlation. For
example, we would probably find no correlation between hours of sleep and shoe size.
As mentioned earlier, correlations have predictive value. Imagine that you are on the admissions committee of a
major university. You are faced with a huge number of applications, but you are able to accommodate only a
small percentage of the applicant pool. How might you decide who should be admitted? You might try to correlate
your current students’ college GPA with their scores on standardized tests like the SAT or ACT. By observing
which correlations were strongest for your current students, you could use this information to predict relative
success of those students who have applied for admission into the university.

LINK TO LEARNINGLINK TO LEARNING
Manipulate this interactive scatterplot to practice your understanding of positive and negative correlation.
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Figure 1. Scatterplots are a graphical view of the strength and direction of correlations. The stronger the correlation, the closer the
data points are to a straight line. In these examples, we see that there is (a) a positive correlation between weight and height, (b) a
negative correlation between tiredness and hours of sleep, and (c) no correlation between shoe size and hours of sleep.

http://www.bc.edu/research/intasc/library/correlation.shtml

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LINK TO LEARNINGLINK TO LEARNING
Watch this clip from Freakonomics for an example of how correlation does not indicate causation.
Correlation Does Not Indicate Causation
Correlational research is useful because it allows us to discover the strength and direction of relationships that
exist between two variables. However, correlation is limited because establishing the existence of a relationship
tells us little about cause and effectcause and effect. While variables are sometimes correlated because one does cause the other,
it could also be that some other factor, a confounding variableconfounding variable, is actually causing the systematic movement in our
variables of interest. In the ice cream/crime rate example mentioned earlier, temperature is a confounding
variable that could account for the relationship between the two variables.
Even when we cannot point to clear confounding variables, we should not assume that a correlation between two
variables implies that one variable causes changes in another. This can be frustrating when a cause-and-effect
relationship seems clear and intuitive. Think back to our discussion of the research done by the American Cancer
Society and how their research projects were some of the first demonstrations of the link between smoking and
cancer. It seems reasonable to assume that smoking causes cancer, but if we were limited to correlationalcorrelational
researchresearch, we would be overstepping our bounds by making this assumption.
Unfortunately, people mistakenly make claims of causation as a function of correlations all the time. Such claims
are especially common in advertisements and news stories. For example, recent research found that people who
eat cereal on a regular basis achieve healthier weights than those who rarely eat cereal (Frantzen, Treviño,
Echon, Garcia-Dominic, & DiMarco, 2013; Barton et al., 2005). Guess how the cereal companies report this
finding. Does eating cereal really cause an individual to maintain a healthy weight, or are there other possible
explanations, such as, someone at a healthy weight is more likely to regularly eat a healthy breakfast than
someone who is obese or someone who avoids meals in an attempt to diet (Figure 2)? While correlational
research is invaluable in identifying relationships among variables, a major limitation is the inability to establish
causality. Psychologists want to make statements about cause and effect, but the only way to do that is to
conduct an experiment to answer a research question. The next section describes how scientific experiments
incorporate methods that eliminate, or control for, alternative explanations, which allow researchers to explore
how changes in one variable cause changes in another variable.

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Figure 2. Does eating cereal really cause someone to be
a healthy weight? (credit: Tim Skillern)
Illusory Correlations
The temptation to make erroneous cause-and-effect
statements based on correlational research is not the only
way we tend to misinterpret data. We also tend to make the
mistake of illusory correlations, especially with unsystematic
observations. Illusory correlationsIllusory correlations, or false correlations,
occur when people believe that relationships exist between
two things when no such relationship exists. One well-
known illusory correlation is the supposed effect that the
moon’s phases have on human behavior. Many people
passionately assert that human behavior is affected by the
phase of the moon, and specifically, that people act
strangely when the moon is full (Figure 3).

Many people believe that a full moon makes people
behave oddly. (credit: Cory Zanker)
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There is no denying that the moon exerts a powerful
influence on our planet. The ebb and flow of the ocean’s
tides are tightly tied to the gravitational forces of the moon.
Many people believe, therefore, that it is logical that we are
affected by the moon as well. After all, our bodies are
largely made up of water. A meta-analysis of nearly 40
studies consistently demonstrated, however, that the
relationship between the moon and our behavior does not
exist (Rotton & Kelly, 1985). While we may pay more
attention to odd behavior during the full phase of the moon,
the rates of odd behavior remain constant throughout the
lunar cycle.
Why are we so apt to believe in illusory correlations like
this? Often we read or hear about them and simply accept
the information as valid. Or, we have a hunch about how
something works and then look for evidence to support that
hunch, ignoring evidence that would tell us our hunch is
false; this is known as confirmation biasconfirmation bias. Other times, we find illusory correlations based on the information that
comes most easily to mind, even if that information is severely limited. And while we may feel confident that we
can use these relationships to better understand and predict the world around us, illusory correlations can have
significant drawbacks. For example, research suggests that illusory correlations—in which certain behaviors are
inaccurately attributed to certain groups—are involved in the formation of prejudicial attitudes that can ultimately
lead to discriminatory behavior (Fiedler, 2004).
THINK IT OVERTHINK IT OVER
We all have a tendency to make illusory correlations from time to time. Try to think of an illusory correlation that
is held by you, a family member, or a close friend. How do you think this illusory correlation came about and
what can be done in the future to combat them?

GLOSSARYGLOSSARY
cause-and-effect relationship:cause-and-effect relationship: changes in one variable cause the changes in the other variable; can be
determined only through an experimental research design
confirmation bias:confirmation bias: tendency to ignore evidence that disproves ideas or beliefs
confounding variable:confounding variable: unanticipated outside factor that affects both variables of interest, often giving the false
impression that changes in one variable causes changes in the other variable, when, in actuality, the outside
factor causes changes in both variables
correlation:correlation: relationship between two or more variables; when two variables are correlated, one variable
changes as the other does
correlation coefficient:correlation coefficient: number from -1 to +1, indicating the strength and direction of the relationship between
variables, and usually represented by r
illusory correlation:illusory correlation: seeing relationships between two things when in reality no such relationship exists
negative correlation:negative correlation: two variables change in different directions, with one becoming larger as the other
becomes smaller; a negative correlation is not the same thing as no correlation
positive correlationpositive correlation two variables change in the same direction, both becoming either larger or smaller
Licensing & AttributionsLicensing & Attributions
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• Correlation vs. Causality: Freakonomics Movie. Located atLocated at: https://www.youtube.com/watch?v=lbODqslc4Tg. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License
EXPERIMENTS
LEARNING OBJECTIVESLEARNING OBJECTIVES
• Describe the experimental process, including ways to control for bias
• Identify and differentiate between independent and dependent variables
Causality: Conducting Experiments and Using the Data
As you’ve learned, the only way to establish that there is a cause-and-effect relationship between two variables is
to conduct a scientific experiment. ExperimentExperiment has a different meaning in the scientific context than in everyday
life. In everyday conversation, we often use it to describe trying something for the first time, such as
experimenting with a new hair style or a new food. However, in the scientific context, an experiment has precise
requirements for design and implementation.
The Experimental Hypothesis
In order to conduct an experiment, a researcher must have a specific hypothesishypothesis to be tested. As you’ve learned,
hypotheses can be formulated either through direct observation of the real world or after careful review of
previous research. For example, if you think that children should not be allowed to watch violent programming on
television because doing so would cause them to behave more violently, then you have basically formulated a

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Figure 1. Seeing behavior like this right after a child
watches violent television programming might lead you to
hypothesize that viewing violent television programming
leads to an increase in the display of violent behaviors.
(credit: Emran Kassim)
hypothesis—namely, that watching violent television programs causes children to behave more violently. How
might you have arrived at this particular hypothesis? You may have younger relatives who watch cartoons
featuring characters using martial arts to save the world from evildoers, with an impressive array of punching,
kicking, and defensive postures. You notice that after watching these programs for a while, your young relatives
mimic the fighting behavior of the characters portrayed in the cartoon (Figure 1).
These sorts of personal observations are what often lead us
to formulate a specific hypothesis, but we cannot use
limited personal observations and anecdotal evidence to
rigorously test our hypothesis. Instead, to find out if real-
world data supports our hypothesis, we have to conduct an
experiment.
Designing an Experiment
The most basic experimental design involves two groups:
the experimental group and the control group. The two
groups are designed to be the same except for one
difference— experimental manipulation. The experimentalexperimental
groupgroup gets the experimental manipulation—that is, the
treatment or variable being tested (in this case, violent TV
images)—and the control groupcontrol group does not. Since
experimental manipulation is the only difference between
the experimental and control groups, we can be sure that
any differences between the two are due to experimental
manipulation rather than chance.
In our example of how violent television programming might
affect violent behavior in children, we have the experimental
group view violent television programming for a specified
time and then measure their violent behavior. We measure
the violent behavior in our control group after they watch
nonviolent television programming for the same amount of
time. It is important for the control group to be treated
similarly to the experimental group, with the exception that
the control group does not receive the experimental
manipulation. Therefore, we have the control group watch non-violent television programming for the same
amount of time as the experimental group.
We also need to precisely define, or operationalize, what is considered violent and nonviolent. An operationaloperational
definitiondefinition is a description of how we will measure our variables, and it is important in allowing others understand
exactly how and what a researcher measures in a particular experiment. In operationalizing violent behavior, we
might choose to count only physical acts like kicking or punching as instances of this behavior, or we also may
choose to include angry verbal exchanges. Whatever we determine, it is important that we operationalize violent
behavior in such a way that anyone who hears about our study for the first time knows exactly what we mean by
violence. This aids peoples’ ability to interpret our data as well as their capacity to repeat our experiment should
they choose to do so.
Once we have operationalized what is considered violent television programming and what is considered violent
behavior from our experiment participants, we need to establish how we will run our experiment. In this case, we
might have participants watch a 30-minute television program (either violent or nonviolent, depending on their
group membership) before sending them out to a playground for an hour where their behavior is observed and the
number and type of violent acts is recorded.
Ideally, the people who observe and record the children’s behavior are unaware of who was assigned to the
experimental or control group, in order to control for experimenter bias. Experimenter biasExperimenter bias refers to the possibility
that a researcher’s expectations might skew the results of the study. Remember, conducting an experiment
requires a lot of planning, and the people involved in the research project have a vested interest in supporting
their hypotheses. If the observers knew which child was in which group, it might influence how much attention

Figure 2. Providing the control group with a placebo
treatment protects against bias caused by expectancy.
(credit: Elaine and Arthur Shapiro)
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they paid to each child’s behavior as well as how they interpreted that behavior. By being blind to which child is in
which group, we protect against those biases. This situation is a single-blind studysingle-blind study, meaning that one of the
groups (participants) are unaware as to which group they are in (experiment or control group) while the
researcher who developed the experiment knows which participants are in each group.
In a double-blind studydouble-blind study, both the researchers and the
participants are blind to group assignments. Why would a
researcher want to run a study where no one knows who is
in which group? Because by doing so, we can control for
both experimenter and participant expectations. If you are
familiar with the phrase placebo effect, you already have
some idea as to why this is an important consideration. The
placebo effectplacebo effect occurs when people’s expectations or beliefs
influence or determine their experience in a given situation.
In other words, simply expecting something to happen can
actually make it happen.
The placebo effect is commonly described in terms of
testing the effectiveness of a new medication. Imagine that
you work in a pharmaceutical company, and you think you
have a new drug that is effective in treating depression. To
demonstrate that your medication is effective, you run an
experiment with two groups: The experimental group
receives the medication, and the control group does not.
But you don’t want participants to know whether they
received the drug or not.
Why is that? Imagine that you are a participant in this study, and you have just taken a pill that you think will
improve your mood. Because you expect the pill to have an effect, you might feel better simply because you took
the pill and not because of any drug actually contained in the pill—this is the placebo effect.
To make sure that any effects on mood are due to the drug and not due to expectations, the control group
receives a placebo (in this case a sugar pill). Now everyone gets a pill, and once again neither the researcher nor
the experimental participants know who got the drug and who got the sugar pill. Any differences in mood between
the experimental and control groups can now be attributed to the drug itself rather than to experimenter bias or
participant expectations (Figure 2).
Independent and Dependent Variables
In a research experiment, we strive to study whether changes in one thing cause changes in another. To achieve
this, we must pay attention to two important variables, or things that can be changed, in any experimental study:
the independent variable and the dependent variable. An independent variableindependent variable is manipulated or controlled by the
experimenter. In a well-designed experimental study, the independent variable is the only important difference
between the experimental and control groups. In our example of how violent television programs affect children’s
display of violent behavior, the independent variable is the type of program—violent or nonviolent—viewed by

Figure 3. In an experiment, manipulations of the independent variable are expected to result in changes in the dependent variable.
(credit “automatic weapon”: modification of work by Daniel Oines; credit “toy gun”: modification of work by Emran Kassim)
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participants in the study (Figure 3). A dependent variabledependent variable is what the researcher measures to see how much
effect the independent variable had. In our example, the dependent variable is the number of violent acts
displayed by the experimental participants.
We expect that the dependent variable will change as a function of the independent variable. In other words, the
dependent variable depends on the independent variable. A good way to think about the relationship between the
independent and dependent variables is with this question: What effect does the independent variable have on
the dependent variable? Returning to our example, what effect does watching a half hour of violent television
programming or nonviolent television programming have on the number of incidents of physical aggression
displayed on the playground?
Selecting and Assigning Experimental Participants
Now that our study is designed, we need to obtain a sample of individuals to include in our experiment. Our study
involves human participants so we need to determine who to include. ParticipantsParticipants are the subjects of
psychological research, and as the name implies, individuals who are involved in psychological research actively
participate in the process. Often, psychological research projects rely on college students to serve as participants.
In fact, the vast majority of research in psychology subfields has historically involved students as research
participants (Sears, 1986; Arnett, 2008). But are college students truly representative of the general population?
College students tend to be younger, more educated, more liberal, and less diverse than the general population.

Figure 4. Researchers may work with (a) a large population or (b) a sample group that is a subset of the larger population. (credit
“crowd”: modification of work by James Cridland; credit “students”: modification of work by Laurie Sullivan)
Although using students as test subjects is an accepted practice, relying on such a limited pool of research
participants can be problematic because it is difficult to generalize findings to the larger population.
Our hypothetical experiment involves children, and we must first generate a sample of child participants. Samples
are used because populations are usually too large to reasonably involve every member in our particular
experiment (Figure 4). If possible, we should use a random samplerandom sample (there are other types of samples, but for the
purposes of this section, we will focus on random samples). A random sample is a subset of a larger population in
which every member of the population has an equal chance of being selected. Random samples are preferred
because if the sample is large enough we can be reasonably sure that the participating individuals are
representative of the larger population. This means that the percentages of characteristics in the sample—sex,
ethnicity, socioeconomic level, and any other characteristics that might affect the results—are close to those
percentages in the larger population.
In our example, let’s say we decide our population of interest is fourth graders. But all fourth graders is a very
large population, so we need to be more specific; instead we might say our population of interest is all fourth
graders in a particular city. We should include students from various income brackets, family situations, races,
ethnicities, religions, and geographic areas of town. With this more manageable population, we can work with the
local schools in selecting a random sample of around 200 fourth graders who we want to participate in our
experiment.
In summary, because we cannot test all of the fourth graders in a city, we want to find a group of about 200 that
reflects the composition of that city. With a representative group, we can generalize our findings to the larger
population without fear of our sample being biased in some way.
Now that we have a sample, the next step of the experimental process is to split the participants into experimental
and control groups through random assignment. With random assignmentrandom assignment, all participants have an equal chance
of being assigned to either group. There is statistical software that will randomly assign each of the fourth graders
in the sample to either the experimental or the control group.
Random assignment is critical for sound experimental designexperimental design. With sufficiently large samples, random assignment
makes it unlikely that there are systematic differences between the groups. So, for instance, it would be very
unlikely that we would get one group composed entirely of males, a given ethnic identity, or a given religious
ideology. This is important because if the groups were systematically different before the experiment began, we
would not know the origin of any differences we find between the groups: Were the differences preexisting, or
were they caused by manipulation of the independent variable? Random assignment allows us to assume that
any differences observed between experimental and control groups result from the manipulation of the
independent variable.

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LINK TO LEARNINGLINK TO LEARNING
Learn more about descriptive, correlational, and experimental approaches to psychological research
through the following PsychSim Tutorial. The tutorial is only intended for practice. Please disregard the final
screen that requests you submit answers to your instructor.
◦ What’s Wrong With This Study
Issues to Consider
While experiments allow scientists to make cause-and-effect claims, they are not without problems. True
experiments require the experimenter to manipulate an independent variable, and that can complicate many
questions that psychologists might want to address. For instance, imagine that you want to know what effect sex
(the independent variable) has on spatial memory (the dependent variable). Although you can certainly look for
differences between males and females on a task that taps into spatial memory, you cannot directly control a
person’s sex. We categorize this type of research approach as quasi-experimental and recognize that we cannot
make cause-and-effect claims in these circumstances.
Experimenters are also limited by ethical constraints. For instance, you would not be able to conduct an
experiment designed to determine if experiencing abuse as a child leads to lower levels of self-esteem among
adults. To conduct such an experiment, you would need to randomly assign some experimental participants to a
group that receives abuse, and that experiment would be unethical.

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GLOSSARYGLOSSARY
cause-and-effect relationship:cause-and-effect relationship: changes in one variable cause the changes in the other variable; can be
determined only through an experimental research design
confirmation bias:confirmation bias: tendency to ignore evidence that disproves ideas or beliefs
control group:control group: serves as a basis for comparison and controls for chance factors that might influence the results
of the study—by holding such factors constant across groups so that the experimental manipulation is the only
difference between groups
correlation:correlation: relationship between two or more variables; when two variables are correlated, one variable
changes as the other does
dependent variable:dependent variable: variable that the researcher measures to see how much effect the independent variable
had
double-blind study:double-blind study: experiment in which both the researchers and the participants are blind to group
assignments
experimental group:experimental group: group designed to answer the research question; experimental manipulation is the only
difference between the experimental and control groups, so any differences between the two are due to
experimental manipulation rather than chance
experimenter bias:experimenter bias: researcher expectations skew the results of the study
independent variable:independent variable: variable that is influenced or controlled by the experimenter; in a sound experimental
study, the independent variable is the only important difference between the experimental and control group
operational definition:operational definition: description of what actions and operations will be used to measure the dependent
variables and manipulate the independent variables
participants:participants: subjects of psychological research
placebo effect:placebo effect: people’s expectations or beliefs influencing or determining their experience in a given situation
random assignment:random assignment: method of experimental group assignment in which all participants have an equal chance
of being assigned to either group
random sample:random sample: subset of a larger population in which every member of the population has an equal chance of
being selected
replicate:replicate: repeating an experiment using different samples to determine the research’s reliability
single-blind study:single-blind study: experiment in which the researcher knows which participants are in the experimental group
and which are in the control group
statistical analysis:statistical analysis: determines how likely any difference between experimental groups is due to chance
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STATISTICAL THINKING
What you’ll learn to do: define basic elements of a statistical
investigation
Once a psychologist has performed an experiment or study and gathered her results, she needs to organize the
information in a way so that she can draw conclusions from the results. What does the information mean? Does it
support or reject the hypothesis? Is the data valid and reliable, and is the study replicable?
Psychologists use statistics to assist them in analyzing data, and also to give more precise measurements to
describe whether something is statistically significant. Analyzing data using statistics enables researchers to find
patterns, make claims, and share their results with others. In this section, you’ll learn about some of the tools that
psychologists use in statistical analysis.
LEARNING OBJECTIVESLEARNING OBJECTIVES
• Define reliability and validity
• Describe the importance of distributional thinking and the role of p-values in statistical inference
• Describe the role of random sampling and random assignment in drawing cause-and-effect
conclusions
Interpreting Experimental Findings
Once data is collected from both the experimental and the control groups, a statistical analysis is conducted to
find out if there are meaningful differences between the two groups. A statistical analysis determines how likely

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LINK TO LEARNINGLINK TO LEARNING
The Online Writing Lab (OWL) at Purdue University can walk you through the APA writing guidelines.
DIG DEEPER: THE VACCINE-AUTISM MYTH AND THE RETRACTION OFDIG DEEPER: THE VACCINE-AUTISM MYTH AND THE RETRACTION OF
PUBLISHED STUDIESPUBLISHED STUDIES
Some scientists have claimed that routine childhood vaccines cause some children to develop autism, and, in
fact, several peer-reviewed publications published research making these claims. Since the initial reports,
large-scale epidemiological research has suggested that vaccinations are not responsible for causing autism
any difference found is due to chance (and thus not meaningful). In psychology, group differences are considered
meaningful, or significant, if the odds that these differences occurred by chance alone are 5 percent or less.
Stated another way, if we repeated this experiment 100 times, we would expect to find the same results at least
95 times out of 100.
The greatest strength of experiments is the ability to assert that any significant differences in the findings are
caused by the independent variable. This occurs because random selection, random assignment, and a design
that limits the effects of both experimenter bias and participant expectancy should create groups that are similar in
composition and treatment. Therefore, any difference between the groups is attributable to the independent
variable, and now we can finally make a causal statement. If we find that watching a violent television program
results in more violent behavior than watching a nonviolent program, we can safely say that watching violent
television programs causes an increase in the display of violent behavior.
Reporting Research
When psychologists complete a research project, they generally want to share their findings with other scientists.
The American Psychological Association (APA) publishes a manual detailing how to write a paper for submission
to scientific journals. Unlike an article that might be published in a magazine like Psychology Today, which targets
a general audience with an interest in psychology, scientific journals generally publish peer-reviewed journal
articles aimed at an audience of professionals and scholars who are actively involved in research themselves.
A peer-reviewed journal article is read by several other scientists (generally anonymously) with expertise in the
subject matter. These peer reviewers provide feedback—to both the author and the journal editor—regarding the
quality of the draft. Peer reviewers look for a strong rationale for the research being described, a clear description
of how the research was conducted, and evidence that the research was conducted in an ethical manner. They
also look for flaws in the study’s design, methods, and statistical analyses. They check that the conclusions drawn
by the authors seem reasonable given the observations made during the research. Peer reviewers also comment
on how valuable the research is in advancing the discipline’s knowledge. This helps prevent unnecessary
duplication of research findings in the scientific literature and, to some extent, ensures that each research article
provides new information. Ultimately, the journal editor will compile all of the peer reviewer feedback and
determine whether the article will be published in its current state (a rare occurrence), published with revisions, or
not accepted for publication.
Peer review provides some degree of quality control for psychological research. Poorly conceived or executed
studies can be weeded out, and even well-designed research can be improved by the revisions suggested. Peer
review also ensures that the research is described clearly enough to allow other scientists to replicate it, meaning
they can repeat the experiment using different samples to determine reliability. Sometimes replications involve
additional measures that expand on the original finding. In any case, each replication serves to provide more
evidence to support the original research findings. Successful replications of published research make scientists
more apt to adopt those findings, while repeated failures tend to cast doubt on the legitimacy of the original article
and lead scientists to look elsewhere. For example, it would be a major advancement in the medical field if a
published study indicated that taking a new drug helped individuals achieve a healthy weight without changing
their diet. But if other scientists could not replicate the results, the original study’s claims would be questioned.

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and that it is much safer to have your child vaccinated than not. Furthermore, several of the original studies
making this claim have since been retracted.
A published piece of work can be rescinded when data is called into question because of falsification,
fabrication, or serious research design problems. Once rescinded, the scientific community is informed that
there are serious problems with the original publication. Retractions can be initiated by the researcher who led
the study, by research collaborators, by the institution that employed the researcher, or by the editorial board of
the journal in which the article was originally published. In the vaccine-autism case, the retraction was made
because of a significant conflict of interest in which the leading researcher had a financial interest in
establishing a link between childhood vaccines and autism (Offit, 2008). Unfortunately, the initial studies
received so much media attention that many parents around the world became hesitant to have their children
vaccinated (Figure 1). For more information about how the vaccine/autism story unfolded, as well as the
repercussions of this story, take a look at Paul Offit’s book, Autism’s False Prophets: Bad Science, Risky
Medicine, and the Search for a Cure.

Figure 1. Some people still think vaccinations cause autism. (credit: modification of work by UNICEF Sverige)
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EVERYDAY CONNECTION: HOW VALID IS THE SAT?EVERYDAY CONNECTION: HOW VALID IS THE SAT?
Standardized tests like the SAT are supposed to measure an individual’s aptitude for a college education, but
how reliable and valid are such tests? Research conducted by the College Board suggests that scores on the
SAT have high predictive validity for first-year college students’ GPA (Kobrin, Patterson, Shaw, Mattern, &
Barbuti, 2008). In this context, predictive validity refers to the test’s ability to effectively predict the GPA of
college freshmen. Given that many institutions of higher education require the SAT for admission, this high
degree of predictive validity might be comforting.
However, the emphasis placed on SAT scores in college admissions has generated some controversy on a
number of fronts. For one, some researchers assert that the SAT is a biased test that places minority students
at a disadvantage and unfairly reduces the likelihood of being admitted into a college (Santelices & Wilson,
2010). Additionally, some research has suggested that the predictive validity of the SAT is grossly exaggerated
in how well it is able to predict the GPA of first-year college students. In fact, it has been suggested that the
SAT’s predictive validity may be overestimated by as much as 150% (Rothstein, 2004). Many institutions of
higher education are beginning to consider de-emphasizing the significance of SAT scores in making admission
decisions (Rimer, 2008).
In 2014, College Board president David Coleman expressed his awareness of these problems, recognizing that
college success is more accurately predicted by high school grades than by SAT scores. To address these
concerns, he has called for significant changes to the SAT exam (Lewin, 2014).
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Reliability and Validity
ReliabilityReliability and validityvalidity are two important considerations that must be made with any type of data collection.
Reliability refers to the ability to consistently produce a given result. In the context of psychological research, this
would mean that any instruments or tools used to collect data do so in consistent, reproducible ways.
Unfortunately, being consistent in measurement does not necessarily mean that you have measured something
correctly. To illustrate this concept, consider a kitchen scale that would be used to measure the weight of cereal
that you eat in the morning. If the scale is not properly calibrated, it may consistently under- or overestimate the
amount of cereal that’s being measured. While the scale is highly reliable in producing consistent results (e.g., the
same amount of cereal poured onto the scale produces the same reading each time), those results are incorrect.
This is where validity comes into play. Validity refers to the extent to which a given instrument or tool accurately
measures what it’s supposed to measure. While any valid measure is by necessity reliable, the reverse is not
necessarily true. Researchers strive to use instruments that are both highly reliable and valid.

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Figure 1. People around the world differ in their
preferences for drinking coffee versus drinking tea. Would
the results of the coffee study be the same in Canada as
in China? [Image: Duncan, https://goo.gl/vbMyTm, CC
BY-NC 2.0, https://goo.gl/l8UUGY]
Introduction to Statistical Thinking
Does drinking coffee actually increase your life expectancy?
A recent study (Freedman, Park, Abnet, Hollenbeck, &
Sinha, 2012) found that men who drank at least six cups of
coffee a day had a 10% lower chance of dying (women
15% lower) than those who drank none. Does this mean
you should pick up or increase your own coffee habit?
Modern society has become awash in studies such as this;
you can read about several such studies in the news every
day.Conducting such a study well, and interpreting the
results of such studies requires understanding basic ideas
of statisticsstatistics, the science of gaining insight from data. Key
components to a statistical investigation are:
• Planning the study: Start by asking a testable
research question and deciding how to collect
data. For example, how long was the study period
of the coffee study? How many people were
recruited for the study, how were they recruited,
and from where? How old were they? What other
variables were recorded about the individuals?
Were changes made to the participants’ coffee
habits during the course of the study?
• Examining the data: What are appropriate ways to
examine the data? What graphs are relevant, and what do they reveal? What descriptive statistics can
be calculated to summarize relevant aspects of the data, and what do they reveal? What patterns do you
see in the data? Are there any individual observations that deviate from the overall pattern, and what do
they reveal? For example, in the coffee study, did the proportions differ when we compared the smokers
to the non-smokers?
• Inferring from the data: What are valid statistical methods for drawing inferences “beyond” the data you
collected? In the coffee study, is the 10%–15% reduction in risk of death something that could have
happened just by chance?
• Drawing conclusions: Based on what you learned from your data, what conclusions can you draw? Who
do you think these conclusions apply to? (Were the people in the coffee study older? Healthy? Living in
cities?) Can you draw a cause-and-effectcause-and-effect conclusion about your treatments? (Are scientists now saying
that the coffee drinking is the cause of the decreased risk of death?)
Notice that the numerical analysis (“crunching numbers” on the computer) comprises only a small part of overall
statistical investigation. In this section, you will see how we can answer some of these questions and what
questions you should be asking about any statistical investigation you read about.
Distributional Thinking
When data are collected to address a particular question, an important first step is to think of meaningful ways to
organize and examine the data. Let’s take a look at an example.
Example 1Example 1: Researchers investigated whether cancer pamphlets are written at an appropriate level to be read
and understood by cancer patients (Short, Moriarty, & Cooley, 1995). Tests of reading ability were given to 63
patients. In addition, readability level was determined for a samplesample of 30 pamphlets, based on characteristics such

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Testing these two variables reveal two fundamental aspects of statistical thinking:
Figure 2: Comparison of patient reading levels and pamphlet readability levels.
as the lengths of words and sentences in the pamphlet. The results, reported in terms of grade levels, are
displayed in Table 1.
Table 1. Frequency tables of patient reading levels and pamphlet readability levels.
• Data vary. More
specifically, values of a variable (such as reading level of a cancer patient or readability level of a cancer
pamphlet) vary.
• Analyzing the pattern of variation, called the distributiondistribution of the variable, often reveals insights.
Addressing the research question of whether the cancer pamphlets are written at appropriate levels for the cancer
patients requires comparing the two distributions. A naïve comparison might focus only on the centers of the
distributions. Both medians turn out to be ninth grade, but considering only medians ignores the variability and the
overall distributions of these data. A more illuminating approach is to compare the entire distributions, for example
with a graph, as in Figure 2.

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TRY ITTRY IT
Figure 2 makes clear that the two distributions are not well aligned at all. The most glaring discrepancy is that
many patients (17/63, or 27%, to be precise) have a reading level below that of the most readable pamphlet.
These patients will need help to understand the information provided in the cancer pamphlets. Notice that this
conclusion follows from considering the distributions as a whole, not simply measures of center or variability, and
that the graph contrasts those distributions more immediately than the frequency tables.
Statistical Significance
Even when we find patterns in data, often there is still uncertainty in various aspects of the data. For example,
there may be potential for measurement errors (even your own body temperature can fluctuate by almost 1°F
over the course of the day). Or we may only have a “snapshot” of observations from a more long-term process or
only a small subset of individuals from the populationpopulation of interest. In such cases, how can we determine whether
patterns we see in our small set of data is convincing evidence of a systematic phenomenon in the larger process
or population? Let’s take a look at another example.
Example 2Example 2: In a study reported in the November 2007 issue of Nature, researchers investigated whether pre-
verbal infants take into account an individual’s actions toward others in evaluating that individual as appealing or
aversive (Hamlin, Wynn, & Bloom, 2007). In one component of the study, 10-month-old infants were shown a
“climber” character (a piece of wood with “googly” eyes glued onto it) that could not make it up a hill in two tries.
Then the infants were shown two scenarios for the climber’s next try, one where the climber was pushed to the
top of the hill by another character (“helper”), and one where the climber was pushed back down the hill by
another character (“hinderer”). The infant was alternately shown these two scenarios several times. Then the
infant was presented with two pieces of wood (representing the helper and the hinderer characters) and asked to
pick one to play with.
The researchers found that of the 16 infants who made a clear choice, 14 chose to play with the helper toy. One
possible explanation for this clear majority result is that the helping behavior of the one toy increases the infants’
likelihood of choosing that toy. But are there other possible explanations? What about the color of the toy? Well,
prior to collecting the data, the researchers arranged so that each color and shape (red square and blue circle)
would be seen by the same number of infants. Or maybe the infants had right-handed tendencies and so picked
whichever toy was closer to their right hand?
Well, prior to collecting the data, the researchers arranged it so half the infants saw the helper toy on the right and
half on the left. Or, maybe the shapes of these wooden characters (square, triangle, circle) had an effect?
Perhaps, but again, the researchers controlled for this by rotating which shape was the helper toy, the hinderer
toy, and the climber. When designing experiments, it is important to control for as many variables as might affect
the responses as possible. It is beginning to appear that the researchers accounted for all the other plausible
explanations. But there is one more important consideration that cannot be controlled—if we did the study again
with these 16 infants, they might not make the same choices. In other words, there is some randomness inherent
in their selection process.
P-value
Maybe each infant had no genuine preference at all, and it was simply “random luck” that led to 14 infants picking
the helper toy. Although this random component cannot be controlled, we can apply a probability model to
investigate the pattern of results that would occur in the long run if random chance were the only factor.
If the infants were equally likely to pick between the two toys, then each infant had a 50% chance of picking the
helper toy. It’s like each infant tossed a coin, and if it landed heads, the infant picked the helper toy. So if we

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tossed a coin 16 times, could it land heads 14 times? Sure, it’s possible, but it turns out to be very unlikely.
Getting 14 (or more) heads in 16 tosses is about as likely as tossing a coin and getting 9 heads in a row. This
probability is referred to as a p-valuep-value. The p-value represents the likelihood that experimental results happened by
chance. Within psychology, the most common standard for p-values is “p < .05”. What this means is that there is less than a 5% probability that the results happened just by random chance, and therefore a 95% probability that the results reflect a meaningful pattern in human psychology. We call this statistical significancestatistical significance. So, in the study above, if we assume that each infant was choosing equally, then the probability that 14 or more out of 16 infants would choose the helper toy is found to be 0.0021. We have only two logical possibilities: either the infants have a genuine preference for the helper toy, or the infants have no preference (50/50) and an outcome that would occur only 2 times in 1,000 iterations happened in this study. Because this p-value of 0.0021 is quite small, we conclude that the study provides very strong evidence that these infants have a genuine preference for the helper toy. If we compare the p-value to some cut-off value, like 0.05, we see that the p=value is smaller. Because the p- value is smaller than that cut-off value, then we reject the hypothesis that only random chance was at play here. In this case, these researchers would conclude that significantly more than half of the infants in the study chose the helper toy, giving strong evidence of a genuine preference for the toy with the helping behavior. Figure 3. Generalizability is an important research consideration: The results of studies with widely representative samples are more likely to generalize to the population. [Image: Barnacles Budget Accommodation] An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=1892 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=1892 TRY ITTRY IT Generalizability One limitation to the study mentioned previously about the babies choosing the “helper” toy is that the conclusion only applies to the 16 infants in the study. We don’t know much about how those 16 infants were selected. Suppose we want to select a subset of individuals (a samplesample) from a much larger group of individuals (the populationpopulation) in such a way that conclusions from the sample can be generalizedgeneralized to the larger population. This is the question faced by pollsters every day. Example 3Example 3: The General Social Survey (GSS) is a survey on societal trends conducted every other year in the United States. Based on a sample of about 2,000 adult Americans, researchers make claims about what percentage of the U.S. population consider themselves to be “liberal,” what percentage consider themselves “happy,” what percentage feel “rushed” in their daily lives, and many other issues. The key to making these claims about the larger population of all American adults lies in how the sample is selected. The goal is to select a sample that is representative of the population, and a common way to achieve this goal is to select a random samplerandom sample that gives every member of the population an equal chance of being selected for the sample. In its simplest form, random sampling involves numbering every member of the population and then using a computer to randomly select the subset to be surveyed. Most polls don’t operate exactly like this, but they do use probability-based sampling methods to select individuals from nationally representative panels. In 2004, the GSS reported that 817 of 977 respondents (or 83.6%) indicated that they always or sometimes feel rushed. This is a clear majority, but we again need to consider variation due to random sampling. Fortunately, we can use the same probability model we did in the previous example to investigate the probable size of this error. (Note, we can use the coin-tossing model when the actual population size is much, much larger than the sample size, as then we can still consider the probability to be the same for every individual in the sample.) This probability model predicts that the sample result will be within 3 percentage points of the population value (roughly 1 over the square root of the sample size, the margin of errormargin of error). A statistician would conclude, with 95% confidence, that between 80.6% and 86.6% of all adult Americans in 2004 would have responded that they sometimes or always feel rushed. The key to the margin of error is that when we use a probability sampling method, we can make claims about how often (in the long run, with repeated random sampling) the sample result would fall within a certain distance from the unknown population value by chance (meaning by random sampling variation) alone. Conversely, non- random samples are often suspect to bias, meaning the sampling method systematically over-represents some segments of the population and under-represents others. We also still need to consider other sources of bias, such as individuals not responding honestly. These sources of error are not measured by the margin of error. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/10/17150423/generalizability https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/10/17150423/generalizability Figure 4. Creativity scores separated by type of motivation. Cause and Effect Conclusions In many research studies, the primary question of interest concerns differences between groups. Then the question becomes how were the groups formed (e.g., selecting people who already drink coffee vs. those who don’t). In some studies, the researchers actively form the groups themselves. But then we have a similar question—could any differences we observe in the groups be an artifact of that group-formation process? Or maybe the difference we observe in the groups is so large that we can discount a “fluke” in the group-formation process as a reasonable explanation for what we find? Example 4Example 4: A psychology study investigated whether people tend to display more creativity when they are thinking about intrinsic (internal) or extrinsic (external) motivations (Ramsey & Schafer, 2002, based on a study by Amabile, 1985). The subjects were 47 people with extensive experience with creative writing. Subjects began by answering survey questions about either intrinsic motivations for writing (such as the pleasure of self-expression) or extrinsic motivations (such as public recognition). Then all subjects were instructed to write a haiku, and those poems were evaluated for creativity by a panel of judges. The researchers conjectured beforehand that subjects who were thinking about intrinsic motivations would display more creativity than subjects who were thinking about extrinsic motivations. The creativity scores from the 47 subjects in this study are displayed in Figure 4, where higher scores indicate more creativity. In this example, the key question is whether the type of motivation affects creativity scores. In particular, do subjects who were asked about intrinsic motivations tend to have higher creativity scores than subjects who were asked about extrinsic motivations? Figure 4 reveals that both motivation groups saw considerable variability in creativity scores, and these scores have considerable overlap between the groups. In other words, it’s certainly not always the case that those with extrinsic motivations have higher creativity than those with intrinsic motivations, but there may still be a statistical tendency in this direction. (Psychologist Keith Stanovich (2013) refers to people’s difficulties with thinking about such probabilistic tendencies as “the Achilles heel of human cognition.”) The mean creativity score is 19.88 for the intrinsic group, compared to 15.74 for the extrinsic group, which supports the researchers’ conjecture. Yet comparing only the means of the two groups fails to consider the variability of creativity scores in the groups. We can measure variability with statistics using, for instance, the standard deviation: 5.25 for the extrinsic group and 4.40 for the intrinsic group. The standard deviations tell us that most of the creativity scores are within about 5 points of the mean score in each group. We see that the mean score for the intrinsic group lies within one standard deviation of the mean score for extrinsic group. So, although there is a tendency for the creativity scores to be higher in the intrinsic group, on average, the difference is not extremely large. We again want to consider possible explanations for this difference. The study only involved individuals with extensive creative writing experience. Although this limits the population to which we can generalize, it does not explain why the mean creativity score was a bit larger for the intrinsic group than for the extrinsic group. Maybe women tend to receive higher creativity scores? Here is where we need to focus on how the individuals were assigned to the motivation groups. If only women were in the intrinsic motivation group and only men in the extrinsic group, then this would present a problem because we wouldn’t know if the intrinsic group did better because of the different type of motivation or because they were women. However, the researchers guarded against such a problem by randomly assigning the individuals to the motivation groups. Like flipping a coin, each individual was just as likely to be assigned to either type of motivation. Why is this helpful? Because this randomrandom Figure 5. Differences in group means under random assignment alone. THE REPLICATION CRISISTHE REPLICATION CRISIS In recent years, there has been increased effort in the sciences (psychology, medicine, economics, etc.) to redo previous experiments to test their reliability. The findings have been disappointing at times. The Reproducibility Project has attempted to replicate 100 studies within the field of psychology that were published with statistically significant results; they found that many of these results did not replicate well (only 39% produced the same results as the original study). Some did not reach statistical significance when replicated. Others reached statistical significance, but with much weaker effects than in the original study. How could this happen? assignmentassignment tends to balance out all the variables related to creativity we can think of, and even those we don’t think of in advance, between the two groups. So we should have a similar male/female split between the two groups; we should have a similar age distribution between the two groups; we should have a similar distribution of educational background between the two groups; and so on. Random assignment should produce groups that are as similar as possible except for the type of motivation, which presumably eliminates all those other variables as possible explanations for the observed tendency for higher scores in the intrinsic group. But does this always work? No, so by “luck of the draw” the groups may be a little different prior to answering the motivation survey. So then the question is, is it possible that an unlucky random assignment is responsible for the observed difference in creativity scores between the groups? In other words, suppose each individual’s poem was going to get the same creativity score no matter which group they were assigned to, that the type of motivation in no way impacted their score. Then how often would the random-assignment process alone lead to a difference in mean creativity scores as large (or larger) than 19.88 – 15.74 = 4.14 points? We again want to apply to a probability model to approximate a p-valuep-value, but this time the model will be a bit different. Think of writing everyone’s creativity scores on an index card, shuffling up the index cards, and then dealing out 23 to the extrinsic motivation group and 24 to the intrinsic motivation group, and finding the difference in the group means. We (better yet, the computer) can repeat this process over and over to see how often, when the scores don’t change, random assignment leads to a difference in means at least as large as 4.41. Figure 5 shows the results from 1,000 such hypothetical random assignments for these scores. Only 2 of the 1,000 simulated random assignments produced a difference in group means of 4.41 or larger. In other words, the approximate p-value is 2/1000 = 0.002. This small p-value indicates that it would be very surprising for the random assignment process alone to produce such a large difference in group means. Therefore, as with Example 4, we have strong evidence that focusing on intrinsic motivations tends to increase creativity scores, as compared to thinking about extrinsic motivations. Notice that the previous statement implies a cause- and-effect relationship between motivation and creativity score; is such a strong conclusion justified? Yes, because of the random assignment used in the study. That should have balanced out any other variables between the two groups, so now that the small p-value convinces us that the higher mean in the intrinsic group wasn’t just a coincidence, the only reasonable explanation left is the difference in the type of motivation. Can we generalize this conclusion to everyone? Not necessarily—we could cautiously generalize this conclusion to individuals with extensive experience in creative writing similar the individuals in this study, but we would still want to know more about how these individuals were selected to participate. https://osf.io/ezcuj/ • ChanceChance. Psychologist use statistics to confirm that their results did not occur simply because of chance (Within psychology, the most common standard for p-values is “p < .05”. What this means is that there is less than a 5% probability that the results happened just by random chance, and therefore a 95% probability that a results reflects a meaningful pattern in human psychology. We call this statistical significance.) Even though a published study may reveal statistically significant results, there is still a possibility that those results were random. • Publication bias.Publication bias. Psychology research journals are far more likely to publish studies that find statistically significant results than they are studies that fail to find statistically significant results. What this means is that studies that yield results that are not statistically significant are very unlikely to get published. Let’s say that twenty researchers are all studying the same phenomenon. Out of the twenty, one gets statistically significant results, while the other nineteen all get non-significant results. The statistically significant result was likely just a result of randomness, but because of publication bias, that one study’s results are far more likely to be published than are the results of the other nineteen. Note that this “replication crisis” itself does not mean that the original studies were bad, fraudulent, or even wrong. What it means, at its core, is that replication found results that were different from the results of the original studies. These results were sufficiently different that we might no longer be secure in our knowledge of what those results mean. Further replication and testing in other directions might give us a better understanding of why the results were different, but that too will require time and resources. Figure 6. Researchers employ the scientific method that involves a great deal of statistical thinking: generate a hypothesis –> design a study to test that hypothesis –>
conduct the study –> analyze the data –> report the
results. [Image: widdowquinn]
Conclusion
Statistical thinking involves the careful design of a study to
collect meaningful data to answer a focused research
question, detailed analysis of patterns in the data, and
drawing conclusions that go beyond the observed data.
Random sampling is paramount to generalizing results from
our sample to a larger population, and random assignment
is key to drawing cause-and-effect conclusions. With both
kinds of randomness, probability models help us assess
how much random variation we can expect in our results, in
order to determine whether our results could happen by
chance alone and to estimate a margin of error.
So where does this leave us with regard to the coffee study
mentioned previously (the Freedman, Park, Abnet,
Hollenbeck, & Sinha, 2012 found that men who drank at
least six cups of coffee a day had a 10% lower chance of
dying (women 15% lower) than those who drank none)? We
can answer many of the questions:
• This was a 14-year study conducted by
researchers at the National Cancer Institute.
• The results were published in the June issue of the New England Journal of Medicine, a respected, peer-
reviewed journal.
• The study reviewed coffee habits of more than 402,000 people ages 50 to 71 from six states and two
metropolitan areas. Those with cancer, heart disease, and stroke were excluded at the start of the study.
Coffee consumption was assessed once at the start of the study.
• About 52,000 people died during the course of the study.
• People who drank between two and five cups of coffee daily showed a lower risk as well, but the amount
of reduction increased for those drinking six or more cups.
• The sample sizes were fairly large and so the p-values are quite small, even though percent reduction in
risk was not extremely large (dropping from a 12% chance to about 10%–11%).
• Whether coffee was caffeinated or decaffeinated did not appear to affect the results.
• This was an observational study, so no cause-and-effect conclusions can be drawn between coffee
drinking and increased longevity, contrary to the impression conveyed by many news headlines about
this study. In particular, it’s possible that those with chronic diseases don’t tend to drink coffee.

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LEARN MORELEARN MORE
Explore these outside resources to learn more about applied statistics:
• Video about p-values: https://www.youtube.com/watch?v=bVMVGHkt2cg
• Interactive web applets for teaching and learning statistics include the collection
at http://www.rossmanchance.com/applets/
• Inter-university Consortium for Political and Social Research http://www.icpsr.umich.edu/index.html
• The Consortium for the Advancement of Undergraduate Statistics https://www.causeweb.org/
GLOSSARYGLOSSARY
cause-and-effect:cause-and-effect: related to whether we say one variable is causing changes in the other variable, versus other
variables that may be related to these two variables.
distributiondistribution: the pattern of variation in data
generalizabilitygeneralizability: related to whether the results from the sample can be generalized to a larger population.
populationpopulation: a larger collection of individuals that we would like to generalize our results to
p-valuep-value: the probability of observing a particular outcome in a sample, or more extreme, under a conjecture
about the larger population or process
random assignmentrandom assignment: using a probability-based method to divide a sample into treatment groups.
random samplingrandom sampling: using a probability-based method to select a subset of individuals for the sample from the
population.
reliability:reliability: consistency and reproducibility of a given result
samplesample: the collection of individuals on which we collect data
statisticstatistic: a numerical result computed from a sample (e.g., mean, proportion)
statistical significancestatistical significance: a result is statistically significant if it is unlikely to arise by chance alone
validity:validity: accuracy of a given result in measuring what it is designed to measure
margin of errormargin of error: the expected amount of random variation in a statistic; often defined for 95% confidence level.
This study needs to be reviewed in the larger context of similar studies and consistency of results across studies,
with the constant caution that this was not a randomized experiment. Whereas a statistical analysis can still
“adjust” for other potential confounding variables, we are not yet convinced that researchers have identified them
all or completely isolated why this decrease in death risk is evident. Researchers can now take the findings of this
study and develop more focused studies that address new questions.
THINK IT OVERTHINK IT OVER
• Find a recent research article in your field and answer the following: What was the primary research
question? How were individuals selected to participate in the study? Were summary results provided?
How strong is the evidence presented in favor or against the research question? Was random
assignment used? Summarize the main conclusions from the study, addressing the issues of
statistical significance, statistical confidence, generalizability, and cause and effect. Do you agree with
the conclusions drawn from this study, based on the study design and the results presented?
• Is it reasonable to use a random sample of 1,000 individuals to draw conclusions about all U.S.
adults? Explain why or why not.

http://www.rossmanchance.com/applets/

http://www.icpsr.umich.edu/index.html

https://www.causeweb.org/

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LINK TO LEARNINGLINK TO LEARNING
Watch this video for an explanation on how to read scholarly articles. Look closely at the example article shared
just before the two minute mark.
Licensing & AttributionsLicensing & Attributions
CC licensed content, OriginalCC licensed content, Original
• Outcome introduction. Authored byAuthored by: Lumen Learning. LicenseLicense: CC BY-SA: Attribution-ShareAlike
• Modification, adaptation, and original content. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution
• The Replication Crisis in Psychology. Authored byAuthored by: Colin Thomas William. Provided byProvided by: Ivy Tech Community College. LicenseLicense: CC BY: Attribution
• Modification to The Replication Crisis. Authored byAuthored by: Pat Carroll and Lumen Learning. LicenseLicense: CC BY: Attribution
CC licensed content, Shared previouslyCC licensed content, Shared previously
• histogram. Authored byAuthored by: Fisher’s Iris flower data set. Provided byProvided by: Wikipedia. Located atLocated at: https://en.wikipedia.org/wiki/Wikipedia:Meetup/DC/Statistics_Edit-a-thon#/media/File:Fisher_iris_versicolor_sepalwidth.svg.
LicenseLicense: CC BY-SA: Attribution-ShareAlike
• Analyzing Findings. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.48:mfArybye@7/Analyzing-Findings. LicenseLicense: CC BY: Attribution
• Statistical Thinking. Authored byAuthored by: Beth Chance and Allan Rossman . Provided byProvided by: California Polytechnic State University, San Luis Obispo. Located atLocated at: http://nobaproject.com/modules/statistical-thinking. ProjectProject: The
Noba Project. LicenseLicense: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike. License TermsLicense Terms: http://nobaproject.com/license-agreement
HOW TO READ RESEARCH
LEARNING OBJECTIVESLEARNING OBJECTIVES
• Describe the basic structure of a psychological research article
In this course and throughout your academic career, you’ll be reading journal articles (meaning they were
published by experts in a peer-reviewed journal) and reports that explain psychological research. It’s important to
understand the format of these articles so that you can read them strategically and understand the information
presented. Scientific articles vary in content or structure, depending on the type of journal to which they will be
submitted. Psychological articles and many papers in the social sciences follow the writing guidelines and format
dictated by the American Psychological Association (APA). In general, the structure follows: abstract, introduction,
methods, results, discussion, and references.
• AbstractAbstract: the abstract is the concise summary of the article. It summarizes the most important features of
the manuscript, providing the reader with a global first impression on the article. It is generally just one
paragraph that explains the experiment as well as a short synopsis of the results.
• IntroductionIntroduction: this section provides background information about the origin and purpose of performing
the experiment or study. It reviews previous research and presents existing theories on the topic.
• MethodMethod: this section covers the methodologies used to investigate the research question, including the
identification of participants, procedures, and materials as well as a description of the actual procedure.
It should be sufficiently detailed to allow for replication.
• ResultsResults: the results section presents key findings of the research, including reference to indicators of
statistical significance.
• DiscussionDiscussion: this section provides an interpretation of the findings, states their significance for current
research, and derives implications for theory and practice. Alternative interpretations for findings are also
provided, particularly when it is not possible to conclude for the directionality of the effects. In the
discussion, authors also acknowledge the strengths and limitations/weaknesses of the study and offer
concrete directions about for future research.

https://creativecommons.org/licenses/by-sa/4.0/

https://creativecommons.org/licenses/by/4.0/

https://en.wikipedia.org/wiki/Wikipedia:Meetup/DC/Statistics_Edit-a-thon#/media/File:Fisher_iris_versicolor_sepalwidth.svg

https://creativecommons.org/licenses/by-sa/4.0/

http://cnx.org/contents/Sr8Ev5Og@5.48:mfArybye@7/Analyzing-Findings

https://creativecommons.org/licenses/by/4.0/

http://nobaproject.com/modules/statistical-thinking

https://creativecommons.org/licenses/by-nc-sa/4.0/

https://owl.english.purdue.edu/owl/section/2/10/

Practice identifying these key components in the following experiment: Food-Induced Emotional Resonance
Improves Emotion Recognition.
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WATCHING TV IS RELATED TO MATH ABILITYWATCHING TV IS RELATED TO MATH ABILITY
Television is often criticized for having a negative impact on our youth. Everything from aggressive behavior
to obesity in children seems to be blamed on their television viewing habits. On the other hand, TV also
provides us with much of our news and entertainment, and has become a major source of education for
children, with shows like Sesame Street teaching children to count and say the alphabet.
Recently, researchers Ian McAtee and Leo Geraci at Harvard University did some research to examine if TV
watching might have beneficial effects on cognition. The approach was fairly simple. Children between the
ages of 12-14 were either asked to watch a television sitcom or do arithmetic problems, and while they were
doing these activities, images of their brains were recorded using fMRI (functional magnetic resonance
imaging). This technique measures the flow of blood to specific parts of the brain during performance,
allowing scientists to create images of the areas that are activated during cognition.
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Please rate whether you agree or disagree with the following statements about the article. There are no
correct answers.
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LEARNING OBJECTIVESLEARNING OBJECTIVES
• Describe replication and its importance to psychology
This is a little difficult for a psychologist to ask, but here goes: when you think of a “science” which one of these
is more likely to come to mind: physics or psychology?
We suspect you chose “physics” (though we don’t have the data, so maybe not!).
Despite the higher “status” of physics and chemistry in the world of science over psychology, good scientific
reasoning is just as important in psychology. Valid logic, careful methodology, strong results, and empirically
supported conclusions should be sought after regardless of the topic area.
We would like to you to exercise your scientific reasoning using the example below. Read the passage
“Watching TV is Related to Math Ability” and answer a few questions afterwards.

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0167462

Results revealed that similar areas of the parietal lobes were
active during TV watching (the red area of the brain image on the
top) and during arithmetic solving (the red area of the brain image
on the bottom). This area of the brain has been implicated in other
research as being important for abstract thought, suggesting that
both TV watching and arithmetic processing may have beneficial
effects on cognition. “We were somewhat surprised that TV
watching would activate brain areas involved in higher-order
thought processes because TV watching is typically considered a
passive activity,” said McAtee. Added Geraci, “The next step is to
see what specific content on the TV show led to the pattern of
activation that mimicked math performance, so we need to better
understand that aspect of the data. We also need to compare TV
watching to other types of cognitive skills, like reading
comprehension and writing.” Although this is only the beginning to
this type of research, these findings certainly question the
accepted wisdom that the “idiot box” is harmful to children’s
cognitive functioning.
The article was well written.
strongly agree
disagree
agree
strongly agree
The title, “Watching TV is Related to Math Ability” was a good description of the results.
strongly agree
disagree
agree
strongly agree
The scientific argument in the article made sense.
strongly agree
disagree
agree
strongly agree
It is pretty surprising to learn that watching television can improve your math ability, and the fact that we can
identify the area in the brain that produces this relationship shows how far psychology has progressed as a
science.
Or maybe not.
The article you just read and rated was not an account of real research. Ian McAtee and Leo Geraci are not real
people and the study discussed was never conducted (as far as we know). The article was written by
psychologists David McCabe and Alan Castel for a study they published in 2008. (Note: David P. McCabe &
Alan D. Castel (2008). Seeing is believing: The effect of brain images on judgments of scientific reasoning.

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TRY ITTRY IT
Cognition, 107, 343-352.) They asked people to do exactly what you just did: read this article and two others
and rate them.
McCabe and Castel wondered if people’s biases about science influence the way they judge the information
they read. In other words, if what you are reading looks more scientific, do you assume it is better science?
In recent years, neuroscience has impressed a lot of people as “real science,” when compared to the “soft
science” of psychology. Did you notice the pictures of the brain next to the article that you just read? Do you
think that picture had any influence on your evaluation of the scientific quality of the article? The brain pictures
actually added no new information that was not already in the article itself other than showing you exactly
where in the brain the relevant part of the parietal lobe is located. The red marks are in the same locations in
both brain pictures, but we already knew that “Results revealed that similar areas in the parietal lobes were
active during TV watching…and during arithmetic solving.”
The McCabe & Castel Experiment
McCabe and Castel wrote three brief (fake) scientific articles that appeared to be typical reports like those you
might find in a textbook or news source, all with brain activity as part of the story. In addition to the one you
read (“Watching TV is related to math ability “) others had these titles: “Meditation enhances creative thought”
and “Playing video games benefits attention.”
All of the articles had flawed scientific reasoning. In the “Watching TV is Related to Math Ability” article that you
read, the only “result” that is reported is that a particular brain area (a part of the parietal lobe) is active when a
person is watching TV and when he or she is working on math. The highlighted part of the next sentence is
where the article goes too far: “This area of the brain has been implicated in other research as being important
for abstract thought, suggesting that both tv watching and arithmetic processing may have beneficial effects onsuggesting that both tv watching and arithmetic processing may have beneficial effects on
cognitioncognition.”
The fact that the same area of the brain is active for two different activities does not “suggest” that either one is
beneficial or that there is any interesting similarity in mental or brain activity between the processes. The final
part of the article goes on and on about how this supposedly surprising finding is intriguing and deserves
extensive exploration.
The researchers asked 156 college students to read the three articles and rate them for how much they made
sense scientifically, as well as rating the quality of the writing and the accuracy of the title.
Everybody read exactly the same articles, but the picture that accompanied the article differed according to
create three experimental conditions. For the article in the brain image condition, subjects saw one of the
following brain images to the side of the article:
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Figure 1. Subjects in the experimental condition were shown ONE of the applicable brain images with each article they read.
Graphs are a common and effective way to display results in science and other areas, but most people are so
used to seeing graphs that (according to McCabe and Castel) people should be less impressed by them than
by brain images. The figures below show the graphs that accompanied the three articles for the bar graph
condition. The results shown in the graphs were made up by the experimenters, but what they show is
consistent with the information in the article.
Figure 2. Participants in the bar graph condition were shown ONE of the bar graphs with each article they read.
Finally, in the control condition, the article was presented without any accompanying figure or picture. The
control condition tells us how the subjects rate the articles without any extraneous, but potentially biasing,
illustrations.
The Procedure
Each participant read all three articles: one with a brain image, one with a bar graph, and one without any
illustration (the control condition). Across all the participants, each article was presented approximately the
same number of times in each condition, and the order in which the articles were presented was randomized.

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The Ratings
Immediately after reading each article, the participants rated their agreement with three statements: (a) The
article was well written, (b) The title was a good description of the results, and (c) The scientific reasoning in the
article made sense. Each rating was on a 4-point scale: (score=1) strongly disagree, (score=2) disagree,
(score=3) agree, and (score=4) strongly agree. Remember that the written part of the articles was exactly the
same in all three conditions, so the ratings should have been the same if people were not using the illustrations
to influence their conclusions.
Before going on, let’s make sure you know the basic design of this experiment. In other words, can you identify
the critical variables used in the study according to their function?
Results
RESULTS FOR (A) ACCURACY OF THE TITLE AND (B) QUALITY OF THERESULTS FOR (A) ACCURACY OF THE TITLE AND (B) QUALITY OF THE
WRITINGWRITING
The first two questions for the participants were about (a) the accuracy of the title and (b) the quality of the
writing. These questions were included to assure that the participants had read the articles closely. The
experimenters expected that there would be no differences in the ratings for the three conditions for these
questions. For the question about the title, their prediction was correct. Subjects gave about the same rating to
the titles in all three conditions, agreeing that it was accurate.
For question (b) about the quality of the writing, the experimenters found that the two conditions with
illustrations (the brain images and the bar graphs) were rated higher than the control condition. Apparently just
the presence of an illustration made the writing seem better. This result was not predicted.
RESULTS FOR (C) SCIENTIFIC REASONING ASSESSMENTRESULTS FOR (C) SCIENTIFIC REASONING ASSESSMENT
The main hypothesis behind this study was that subjects would rate the quality of the scientific reasoning in the
article higher when it was accompanied by a brain image than when there was a bar graph or there was no
illustration at all. If the ratings differed among conditions, then the illustrations—which added nothing substantial
that was not in the writing—had to be the cause.

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Use the graph below to show your predicted results of the experiment. Move the bars to the point where you
think people generally agreed or disagreed with the statement that “the scientific reasoning in the article
made sense.” Higher bars mean that the person believes the reasoning in the article is better, and a lower
bar means that they judge the reasoning as worse. Click on “Show Results” when you are done to compare
your prediction with the actual results.
AnswerAnswer
RESULTS: The results supported the experimenters’ prediction. The scientific reasoning for the Brain Image
condition was rated as significantly higher than for either other condition. There was no significant difference
between the Bar Graph condition and the Control condition. Here is a graph of the results:
Conclusions
McCabe and Castel conducted two more experiments, changing the stories, the images, and the wording of the
questions in each. Across the three experiments, they tested almost 400 college students and their results were
consistent: participants rated the quality of scientific reasoning higher when the writing was accompanied by a
brain image than in other conditions.
The implications of this study go beyond brain images. The deeper idea is that any information that symbolizes
something we believe is important can influence our thinking, sometimes making us less thoughtful than we
might otherwise be. This other information could be a brain image or some statistical jargon that sounds
impressive or a mathematical formula that we don’t understand or a statement that the author teaches at
Harvard University rather than Littletown State College.
In a study also published in 2008, Deena Weisberg and her colleagues at Yale University conducted a study
similar to the one you just read. (Note: Deena Skolnick Weisberg, Frank C. Keil, Joshua Goodstein, Elizabeth
Rawson, & Jeremy R. Gray (2008). The seductive allure of neuroscience explanations. Journal of Cognitive
Neuroscience, 20(3), 470-477) Weisberg had people read brief descriptions of psychological phenomena
(involving memory, attention, reasoning, emotion, and other similar topics). They rated the scientific quality of
the explanations. Instead of images, Weisberg had some explanations that included entirely superfluous and
useless brain information (e.g., “people feel strong emotion because the amygdala processes emotion”) or no
such brain information. Weisberg found that a good explanation was rated as even better when it included a
brain reference (which was completely irrelevant). When the explanation was flawed, students were fairly good

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at catching the reasoning problems UNLESS the explanation contained the irrelevant brain reference. In that
case, the students rated the flawed explanations as being good. Weinstein and her colleague call the problem
“the seductive allure of neuroscience explanations.”
Does it Replicate? The Messy World of Real ScienceDoes it Replicate? The Messy World of Real Science
A few years after the McCabe and Castel study was published, some psychologists (Note: Robert B. Michael,
Eryn J. Newman, Matti Vuorre, Geoff Cumming, and Maryanne Garry (2013). On the (non)persuasive power of
a brain image. Psychonomic Bulletin & Review, 20(4), 720-725.) at the University of Victoria in New Zealand,
led by Robert Michael, were intrigued by the results and they were impressed by how frequently the paper had
been cited by other researchers (about 40 citations per year between 2008 and 2012—a reasonably strong
citation record). They wanted to explore the brain image effect, so they started by simply replicating the original
study. (Note: They actually tried to replicate Experiment 3 in the McCabe and Castel study. You read
Experiment 1. These two experiments were similar and supported the same conclusions, but Dr. Michael and
his colleagues preferred Experiment 3 for some technical reasons.)
In their first attempt at replication, the researchers recruited and tested people using an online site called
Mechanical Turk. With 197 participants, they found no hint of an effect of the brain image on people’s
judgments about the validity of the conclusions of the article they read. In a second replication study, they
tested students from their university and again found no statistically significant effect. In this second attempt,
the results were in the predicted direction (the presence of a brain image was associated with higher ratings),
but the differences were not strong enough to be persuasive. They tried slight variations on instructions and
people recruited, but across 10 different replication studies, only one produced a statistically significant effect.
So, did Dr. Michael and his colleagues accuse McCabe and Castel of doing something wrong? Did they tear
apart the experiments we described earlier and show that they were poorly planned, incorrectly analyzed, or
interpreted in a deceptive way?
Not at all.
It is instructive to see how professional scientists approached the problem of failing to replicate a study. Here is
a quick review of the approach taken by the researchers who did not replicate the McCabe and Castel study:
• First, they did not question the integrity of the original research. David McCabe (Note: David McCabe,
the first author of the original paper, tragically passed away in 2011 at the age of 41. At the time of his
death, he was an assistant professor of Psychology at Colorado State University and he had started to
build a solid body of published research, and he was also married with two young children. The
problems with replicating his experiments were only published after his death, so it is impossible to
know what his thoughts might have been about the issues these challenges raised.) and Alan Castel
are respected researchers who carefully reported on a series of well-conducted experiments. They
even noted that the original paper was carefully reported, even if journalists and other psychologists
had occasionally exaggerated the findings: “Although McCabe and Castel (2008) did not overstate
their findings, many others have. Sometimes these overstatements were linguistic
exaggerations…Other overstatements made claims beyond what McCabe and Castel themselves
reported.” [p. 720]
• Replication is an essential part of the scientific process. Michael and his colleagues did not back off of
the importance of their difficulty reproducing the McCabe and Castel results. Clearly, McCabe and
Castel’s conclusions—that “there is something special about the brain images with respect to
influencing judgments of scientific credibility”—need to taken as possibly incorrect.
• Michael and his colleagues looked closely at the McCabe and Castel results and their own, and they
looked for interesting reasons that the results of the two sets of studies might be different.

THE “REPLICATION CRISIS”THE “REPLICATION CRISIS”
In recent years, there has been increased effort in the sciences (psychology, medicine, economics, etc.) to
redo previous experiments to test their reliability. The findings have been disappointing at times.
The Reproducibility Project has attempted to replicate 100 studies within the field of psychology that were
published with statistically significant results; they found that many of these results did not replicate well.
Some did not reach statistical significance when replicated. Others reached statistical significance, but with
much weaker effects than in the original study.
How could this happen?
• ChanceChance. Psychologist use statistics to confirm that their results did not occur simply because of
chance (Within psychology, the most common standard for p-values is “p < .05”. What this means is that there is less than a 5% probability that the results happened just by random chance, and therefore a 95% probability that a results reflects a meaningful pattern in human psychology. We call this statistical significance.) Even though a published study may reveal statistically significant results, there is still a possibility that those results were random. • Publication bias.Publication bias. Psychology research journals are far more likely to publish studies that find statistically significant results than they are studies that fail to find statistically significant results. What this means is that studies that yield results that are not statistically significant are very unlikely to get published. Let’s say that twenty researchers are all studying the same phenomenon. Out of the twenty, one gets statistically significant results, while the other nineteen all get non-significant results. The statistically significant result was likely just a result of randomness, but because of publication bias, that one study’s results are far more likely to be published than are the results of the other nineteen. Note that this “replication crisis” itself does not mean that the original studies were bad, fraudulent, or even wrong. What it means, at its core, is that replication found results that were different from the results of the original studies. These results were sufficiently different that we might no longer be secure in our knowledge of what those results mean. Further replication and testing in other directions might give us a better understanding of why the results were different, but that too will require time and resources. ▪ Subtle effectsSubtle effects: Perhaps the brain pictures really do influence their judgments, but only for some people or under very specific circumstances. ▪ Alternative explanationsAlternative explanations: Perhaps people assume that irrelevant information is not typically presented in scientific reports. People may have believed that the brain images provided additional evidence for the claims. ▪ Things have changedThings have changed: The McCabe and Castel study was conducted in 2008 and the failed replication was in 2013. Neuroscience as very new to the general public in 2008, but a mere 5 years later, in 2013, it may have seemed less impressive. Do images really directly affect people’s judgments of the quality of scientific thinking? Maybe yes. Maybe no. That’s still an open question. One Final Note When we wrote to Dr. Alan Castel for permission to use his stimuli in this article, he not only consented, but he also sent us his data and copies of all of his stimuli. He sent copies of research by a variety of people, some research that has supported his work with David McCabe and some that has not. He even included a copy of the 10-experiment paper that you just read about, the one that failed to replicate the McCabe and Castel study. The goal is to find the truth, not to insist that everything you publish is the last word on the topic. In fact, if it is the last word, then you are probably studying something so boring that no one else really cares. Scientists disagree with one another all the time. But the disagreements are (usually) not personal. The evidence is not always neat and tidy, and the best interpretation of complex results is seldom obvious. At its https://osf.io/ezcuj/ best, it is possible for scientists to disagree passionately about theory and evidence, and later to relax over a cool drink, laugh and talk about friends or sports or life and love. WATCHING TV IS RELATED TO MATH ABILITYWATCHING TV IS RELATED TO MATH ABILITY Television is often criticized for having a negative impact on our youth. Everything from aggressive behavior to obesity in children seems to be blamed on their television viewing habits. On the other hand, TV also provides us with much of our news and entertainment, and has become a major source of education for children, with shows like Sesame Street teaching children to count and say the alphabet. Recently, researchers Ian McAtee and Leo Geraci at Harvard University did some research to examine if TV watching might have beneficial effects on cognition. The approach was fairly simple. Children between the ages of 12-14 were either asked to watch a television sitcom or do arithmetic problems, and while they were doing these activities, images of their brains were recorded using fMRI (functional magnetic resonance imaging). This technique measures the flow of blood to specific parts of the brain during performance, allowing scientists to create images of the areas that are activated during cognition. Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Modification, adaptation, and original content. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution • Brain Imaging and Messy Science. Authored byAuthored by: Patrick Carroll for Lumen Learning. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution CC licensed content, Shared previouslyCC licensed content, Shared previously • Reading a Scientific Paper for Psychology and the Social Sciences: A Critical Guide. Authored byAuthored by: Pedro Cordeiro, Victor E. C. Ortuu00f1o, Maria Paula Paixu00e3o, Jou00e3o Maru00f4co. Provided byProvided by: Faculty of Psychology and Educational Sciences, University of Coimbra. Located atLocated at: http://pch.psychopen.eu/article/view/136/html. LicenseLicense: CC BY: Attribution • What is a Scholarly Article? video. Provided byProvided by: Coastal Carolina University. Located atLocated at: http://www.coastal.edu/intranet/library/videos/browse.html. LicenseLicense: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike • The Replication Crisis. Authored byAuthored by: Colin Thomas William. Provided byProvided by: Ivy Tech Community College. LicenseLicense: CC BY: Attribution All rights reserved contentAll rights reserved content • Seeing is believing: The effect of brain images on judgments of scientific reasoning. Authored byAuthored by: David P. McCabe & Alan D. Castel (2008). Provided byProvided by: Cognition. LicenseLicense: All Rights Reserved. License TermsLicense Terms: Used with permission from Alan Castel PSYCH IN REAL LIFE: BRAIN IMAGING AND MESSY SCIENCE LEARNING OBJECTIVESLEARNING OBJECTIVES • Describe replication and its importance to psychology This is a little difficult for a psychologist to ask, but here goes: when you think of a “science” which one of these is more likely to come to mind: physics or psychology? We suspect you chose “physics” (though we don’t have the data, so maybe not!). Despite the higher “status” of physics and chemistry in the world of science over psychology, good scientific reasoning is just as important in psychology. Valid logic, careful methodology, strong results, and empirically supported conclusions should be sought after regardless of the topic area. We would like to you to exercise your scientific reasoning using the example below. Read the passage “Watching TV is Related to Math Ability” and answer a few questions afterwards. https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ http://pch.psychopen.eu/article/view/136/html https://creativecommons.org/licenses/by/4.0/ http://www.coastal.edu/intranet/library/videos/browse.html https://creativecommons.org/licenses/by-nc-sa/4.0/ https://creativecommons.org/licenses/by/4.0/ Results revealed that similar areas of the parietal lobes were active during TV watching (the red area of the brain image on the top) and during arithmetic solving (the red area of the brain image on the bottom). This area of the brain has been implicated in other research as being important for abstract thought, suggesting that both TV watching and arithmetic processing may have beneficial effects on cognition. “We were somewhat surprised that TV watching would activate brain areas involved in higher-order thought processes because TV watching is typically considered a passive activity,” said McAtee. Added Geraci, “The next step is to see what specific content on the TV show led to the pattern of activation that mimicked math performance, so we need to better understand that aspect of the data. We also need to compare TV watching to other types of cognitive skills, like reading comprehension and writing.” Although this is only the beginning to this type of research, these findings certainly question the accepted wisdom that the “idiot box” is harmful to children’s cognitive functioning. TRY ITTRY IT Please rate whether you agree or disagree with the following statements about the article. There are no correct answers. The article was well written. strongly agree disagree agree strongly agree The title, “Watching TV is Related to Math Ability” was a good description of the results. strongly agree disagree agree strongly agree The scientific argument in the article made sense. strongly agree disagree agree strongly agree It is pretty surprising to learn that watching television can improve your math ability, and the fact that we can identify the area in the brain that produces this relationship shows how far psychology has progressed as a science. Or maybe not. The article you just read and rated was not an account of real research. Ian McAtee and Leo Geraci are not real people and the study discussed was never conducted (as far as we know). The article was written by psychologists David McCabe and Alan Castel for a study they published in 2008. (Note: David P. McCabe & Alan https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/07/03123719/Screen-Shot-2017-08-03-at-7.32.47-AM1 https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/07/03123719/Screen-Shot-2017-08-03-at-7.32.47-AM1 TRY ITTRY IT https://assessments.lumenlearning.com/assessments/11316 D. Castel (2008). Seeing is believing: The effect of brain images on judgments of scientific reasoning. Cognition, 107, 343-352.) They asked people to do exactly what you just did: read this article and two others and rate them. McCabe and Castel wondered if people’s biases about science influence the way they judge the information they read. In other words, if what you are reading looks more scientific, do you assume it is better science? In recent years, neuroscience has impressed a lot of people as “real science,” when compared to the “soft science” of psychology. Did you notice the pictures of the brain next to the article that you just read? Do you think that picture had any influence on your evaluation of the scientific quality of the article? The brain pictures actually added no new information that was not already in the article itself other than showing you exactly where in the brain the relevant part of the parietal lobe is located. The red marks are in the same locations in both brain pictures, but we already knew that “Results revealed that similar areas in the parietal lobes were active during TV watching…and during arithmetic solving.” The McCabe & Castel Experiment McCabe and Castel wrote three brief (fake) scientific articles that appeared to be typical reports like those you might find in a textbook or news source, all with brain activity as part of the story. In addition to the one you read (“Watching TV is related to math ability “) others had these titles: “Meditation enhances creative thought” and “Playing video games benefits attention.” All of the articles had flawed scientific reasoning. In the “Watching TV is Related to Math Ability” article that you read, the only “result” that is reported is that a particular brain area (a part of the parietal lobe) is active when a person is watching TV and when he or she is working on math. The highlighted part of the next sentence is where the article goes too far: “This area of the brain has been implicated in other research as being important for abstract thought, suggesting that both tv watching and arithmetic processing may have beneficial effects onsuggesting that both tv watching and arithmetic processing may have beneficial effects on cognitioncognition.” The fact that the same area of the brain is active for two different activities does not “suggest” that either one is beneficial or that there is any interesting similarity in mental or brain activity between the processes. The final part of the article goes on and on about how this supposedly surprising finding is intriguing and deserves extensive exploration. The researchers asked 156 college students to read the three articles and rate them for how much they made sense scientifically, as well as rating the quality of the writing and the accuracy of the title. Everybody read exactly the same articles, but the picture that accompanied the article differed according to create three experimental conditions. For the article in the brain image condition, subjects saw one of the following brain images to the side of the article: Figure 1. Subjects in the experimental condition were shown ONE of the applicable brain images with each article they read. Graphs are a common and effective way to display results in science and other areas, but most people are so used to seeing graphs that (according to McCabe and Castel) people should be less impressed by them than by brain images. The figures below show the graphs that accompanied the three articles for the bar graph condition. The results shown in the graphs were made up by the experimenters, but what they show is consistent with the information in the article. Figure 2. Participants in the bar graph condition were shown ONE of the bar graphs with each article they read. Finally, in the control condition, the article was presented without any accompanying figure or picture. The control condition tells us how the subjects rate the articles without any extraneous, but potentially biasing, illustrations. The Procedure Each participant read all three articles: one with a brain image, one with a bar graph, and one without any illustration (the control condition). Across all the participants, each article was presented approximately the same number of times in each condition, and the order in which the articles were presented was randomized. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/07/03144210/image3 https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/07/03144210/image3 https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/07/03144302/image2 https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/07/03144302/image2 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=5104 TRY ITTRY IT https://assessments.lumenlearning.com/assessments/11317 TRY ITTRY IT Use the graph below to show your predicted results of the experiment. Move the bars to the point where you think people generally agreed or disagreed with the statement that “the scientific reasoning in the article made sense.” Higher bars mean that the person believes the reasoning in the article is better, and a lower bar means that they judge the reasoning as worse. Click on “Show Results” when you are done to compare your prediction with the actual results. https://s3-us-west-2.amazonaws.com/oerfiles/Psychology/interactives/brain_imaging.html AnswerAnswer The Ratings Immediately after reading each article, the participants rated their agreement with three statements: (a) The article was well written, (b) The title was a good description of the results, and (c) The scientific reasoning in the article made sense. Each rating was on a 4-point scale: (score=1) strongly disagree, (score=2) disagree, (score=3) agree, and (score=4) strongly agree. Remember that the written part of the articles was exactly the same in all three conditions, so the ratings should have been the same if people were not using the illustrations to influence their conclusions. Before going on, let’s make sure you know the basic design of this experiment. In other words, can you identify the critical variables used in the study according to their function? Results RESULTS FOR (a) ACCURACY OF THE TITLE AND (b) QUALITY OF THE WRITING The first two questions for the participants were about (a) the accuracy of the title and (b) the quality of the writing. These questions were included to assure that the participants had read the articles closely. The experimenters expected that there would be no differences in the ratings for the three conditions for these questions. For the question about the title, their prediction was correct. Subjects gave about the same rating to the titles in all three conditions, agreeing that it was accurate. For question (b) about the quality of the writing, the experimenters found that the two conditions with illustrations (the brain images and the bar graphs) were rated higher than the control condition. Apparently just the presence of an illustration made the writing seem better. This result was not predicted. RESULTS FOR (c) SCIENTIFIC REASONING ASSESSMENT The main hypothesis behind this study was that subjects would rate the quality of the scientific reasoning in the article higher when it was accompanied by a brain image than when there was a bar graph or there was no illustration at all. If the ratings differed among conditions, then the illustrations—which added nothing substantial that was not in the writing—had to be the cause. https://s3-us-west-2.amazonaws.com/oerfiles/Psychology/interactives/brain_imaging.html RESULTS: The results supported the experimenters’ prediction. The scientific reasoning for the Brain Image condition was rated as significantly higher than for either other condition. There was no significant difference between the Bar Graph condition and the Control condition. Here is a graph of the results: Conclusions McCabe and Castel conducted two more experiments, changing the stories, the images, and the wording of the questions in each. Across the three experiments, they tested almost 400 college students and their results were consistent: participants rated the quality of scientific reasoning higher when the writing was accompanied by a brain image than in other conditions. The implications of this study go beyond brain images. The deeper idea is that any information that symbolizes something we believe is important can influence our thinking, sometimes making us less thoughtful than we might otherwise be. This other information could be a brain image or some statistical jargon that sounds impressive or a mathematical formula that we don’t understand or a statement that the author teaches at Harvard University rather than Littletown State College. In a study also published in 2008, Deena Weisberg and her colleagues at Yale University conducted a study similar to the one you just read. (Note: Deena Skolnick Weisberg, Frank C. Keil, Joshua Goodstein, Elizabeth Rawson, & Jeremy R. Gray (2008). The seductive allure of neuroscience explanations. Journal of Cognitive Neuroscience, 20(3), 470-477) Weisberg had people read brief descriptions of psychological phenomena (involving memory, attention, reasoning, emotion, and other similar topics). They rated the scientific quality of the explanations. Instead of images, Weisberg had some explanations that included entirely superfluous and useless brain information (e.g., “people feel strong emotion because the amygdala processes emotion”) or no such brain information. Weisberg found that a good explanation was rated as even better when it included a brain reference (which was completely irrelevant). When the explanation was flawed, students were fairly good at catching the reasoning problems UNLESS the explanation contained the irrelevant brain reference. In that case, the students rated the flawed explanations as being good. Weinstein and her colleague call the problem “the seductive allure of neuroscience explanations.” Does it Replicate? The Messy World of Real Science A few years after the McCabe and Castel study was published, some psychologists (Note: Robert B. Michael, Eryn J. Newman, Matti Vuorre, Geoff Cumming, and Maryanne Garry (2013). On the (non)persuasive power of a brain image. Psychonomic Bulletin & Review, 20(4), 720-725.) at the University of Victoria in New Zealand, led by Robert Michael, were intrigued by the results and they were impressed by how frequently the paper had been cited by other researchers (about 40 citations per year between 2008 and 2012—a reasonably strong citation record). They wanted to explore the brain image effect, so they started by simply replicating the original study. (Note: They actually tried to replicate Experiment 3 in the McCabe and Castel study. You read Experiment 1. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/07/03145755/image1 TRY ITTRY IT https://assessments.lumenlearning.com/assessments/11320 These two experiments were similar and supported the same conclusions, but Dr. Michael and his colleagues preferred Experiment 3 for some technical reasons.) In their first attempt at replication, the researchers recruited and tested people using an online site called Mechanical Turk. With 197 participants, they found no hint of an effect of the brain image on people’s judgments about the validity of the conclusions of the article they read. In a second replication study, they tested students from their university and again found no statistically significant effect. In this second attempt, the results were in the predicted direction (the presence of a brain image was associated with higher ratings), but the differences were not strong enough to be persuasive. They tried slight variations on instructions and people recruited, but across 10 different replication studies, only one produced a statistically significant effect. So, did Dr. Michael and his colleagues accuse McCabe and Castel of doing something wrong? Did they tear apart the experiments we described earlier and show that they were poorly planned, incorrectly analyzed, or interpreted in a deceptive way? Not at all. It is instructive to see how professional scientists approached the problem of failing to replicate a study. Here is a quick review of the approach taken by the researchers who did not replicate the McCabe and Castel study: • First, they did not question the integrity of the original research. David McCabe (Note: David McCabe, the first author of the original paper, tragically passed away in 2011 at the age of 41. At the time of his death, he was an assistant professor of Psychology at Colorado State University and he had started to build a solid body of published research, and he was also married with two young children. The problems with replicating his experiments were only published after his death, so it is impossible to know what his thoughts might have been about the issues these challenges raised.) and Alan Castel are respected researchers who carefully reported on a series of well-conducted experiments. They even noted that the original paper was carefully reported, even if journalists and other psychologists had occasionally exaggerated the findings: “Although McCabe and Castel (2008) did not overstate their findings, many others have. Sometimes these overstatements were linguistic exaggerations…Other overstatements made claims beyond what McCabe and Castel themselves reported.” [p. 720] • Replication is an essential part of the scientific process. Michael and his colleagues did not back off of the importance of their difficulty reproducing the McCabe and Castel results. Clearly, McCabe and Castel’s conclusions—that “there is something special about the brain images with respect to influencing judgments of scientific credibility”—need to taken as possibly incorrect. • Michael and his colleagues looked closely at the McCabe and Castel results and their own, and they looked for interesting reasons that the results of the two sets of studies might be different. ▪ Subtle effectsSubtle effects: Perhaps the brain pictures really do influence their judgments, but only for some people or under very specific circumstances. ▪ Alternative explanationsAlternative explanations: Perhaps people assume that irrelevant information is not typically presented in scientific reports. People may have believed that the brain images provided additional evidence for the claims. ▪ Things have changedThings have changed: The McCabe and Castel study was conducted in 2008 and the failed replication was in 2013. Neuroscience as very new to the general public in 2008, but a mere 5 years later, in 2013, it may have seemed less impressive. Do images really directly affect people’s judgments of the quality of scientific thinking? Maybe yes. Maybe no. That’s still an open question. THE “REPLICATION CRISIS”THE “REPLICATION CRISIS” In recent years, there has been increased effort in the sciences (psychology, medicine, economics, etc.) to redo previous experiments to test their reliability. The findings have been disappointing at times. The Reproducibility Project has attempted to replicate 100 studies within the field of psychology that were published with statistically significant results; they found that many of these results did not replicate well. Some did not reach statistical significance when replicated. Others reached statistical significance, but with much weaker effects than in the original study. How could this happen? • ChanceChance. Psychologist use statistics to confirm that their results did not occur simply because of chance. Within psychology, the most common standard for p-values is “p < .05”. This p-value means that there is less than a 5% probability that the results of an experiment happened just by random chance, and a 95% probability that the results were statistically significant. Even though a published study may reveal statistically significant results, there is still a possibility that those results were random. • Publication bias.Publication bias. Psychology research journals are far more likely to publish studies that find statistically significant results than they are studies that fail to find statistically significant results. What this means is that studies that yield results that are not statistically significant are very unlikely to get published. Let’s say that twenty researchers are all studying the same phenomenon. Out of the twenty, one gets statistically significant results, while the other nineteen all get non-significant results. The statistically significant result was likely just a result of randomness, but because of publication bias, that one study’s results are far more likely to be published than are the results of the other nineteen. Note that this “replication crisis” itself does not mean that the original studies were bad, fraudulent, or even wrong. What it means, at its core, is that replication found results that were different from the results of the original studies. These results were sufficiently different that we might no longer be secure in our knowledge of what those results mean. Further replication and testing in other directions might give us a better understanding of why the results were different, but that too will require time and resources. One Final Note When we wrote to Dr. Alan Castel for permission to use his stimuli in this article, he not only consented, but he also sent us his data and copies of all of his stimuli. He sent copies of research by a variety of people, some research that has supported his work with David McCabe and some that has not. He even included a copy of the 10-experiment paper that you just read about, the one that failed to replicate the McCabe and Castel study. The goal is to find the truth, not to insist that everything you publish is the last word on the topic. In fact, if it is the last word, then you are probably studying something so boring that no one else really cares. Scientists disagree with one another all the time. But the disagreements are (usually) not personal. The evidence is not always neat and tidy, and the best interpretation of complex results is seldom obvious. At its best, it is possible for scientists to disagree passionately about theory and evidence, and later to relax over a cool drink, laugh and talk about friends or sports or life and love. Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Brain Imaging and Messy Science. Authored byAuthored by: Patrick Carroll for Lumen Learning. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution CC licensed content, Shared previouslyCC licensed content, Shared previously • The Replication Crisis. Authored byAuthored by: Colin Thomas William. Provided byProvided by: Ivy Tech Community College. LicenseLicense: CC BY: Attribution All rights reserved contentAll rights reserved content • Seeing is believing: The effect of brain images on judgments of scientific reasoning. Authored byAuthored by: David P. McCabe & Alan D. Castel (2008). Provided byProvided by: Cognition. LicenseLicense: All Rights Reserved. License TermsLicense Terms: Used with permission from Alan Castel https://osf.io/ezcuj/ https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=1894 PUTTING IT TOGETHER: PSYCHOLOGICAL RESEARCH LEARNING OBJECTIVESLEARNING OBJECTIVES In this module, you learned to • define and apply the scientific method to psychology • describe the strengths and weaknesses of descriptive, experimental, and correlational research • define the basic elements of a statistical investigation Psychologists use the scientific method to examine human behavior and mental processes. Some of the methods you learned about include descriptive, experimental, and correlational research designs. Watch the CrashCourse video to review the material you learned, then read through the following examples and see if you can come up with your own design for each type of study. Case Study:Case Study: a detailed analysis of a particular person, group, business, event, etc. This approach is commonly used to to learn more about rare examples with the goal of describing that particular thing. • Ted Bundy was one of America’s most notorious serial killers who murdered at least 30 women and was executed in 1989. Dr. Al Carlisle evaluated Bundy when he was first arrested and conducted a psychological analysis of Bundy’s development of his sexual fantasies merging into reality (Ramsland, 2012). Carlisle believes that there was a gradual evolution of three processes that guided his actions: fantasy, dissociation, and compartmentalization (Ramsland, 2012). Read Imagining Ted Bundy (http://goo.gl/rGqcUv) for more information on this case study. Naturalistic ObservationNaturalistic Observation: a researcher unobtrusively collects information without the participant’s awareness. • Drain and Engelhardt (2013) observed six nonverbal children with autism’s evoked and spontaneous communicative acts. Each of the children attended a school for children with autism and were in different classes. They were observed for 30 minutes of each school day. By observing these children without them knowing, they were able to see true communicative acts without any external influences. SurveySurvey: participants are asked to provide information or responses to questions on a survey or structure assessment. • Educational psychologists can ask students to report their grade point average and what, if anything, they eat for breakfast on an average day. A healthy breakfast has been associated with better academic performance (Digangi’s 1999). Archival research:Archival research: researchers examine data that has already been collected for other purposes. • Anderson (1987) tried to find the relationship between uncomfortably hot temperatures and aggressive behavior, which was then looked at with two studies done on violent and nonviolent crime. Based on previous research that had been done by Anderson and Anderson (1984), it was predicted that violent crimes would be more prevalent during the hotter time of year and the years in which it was hotter weather in general. The study confirmed this prediction. Longitudinal Study:Longitudinal Study: researchers recruit a sample of participants and track them for an extended period of time. https://www.psychologytoday.com/blog/shadow-boxing/201208/imagining-ted-bundy https://www.psychologytoday.com/blog/shadow-boxing/201208/imagining-ted-bundy • In a study of a representative sample of 856 children Eron and his colleagues (1972) found that a boy’s exposure to media violence at age eight was significantly related to his aggressive behavior ten years later, after he graduated from high school. Cross-Sectional Study:Cross-Sectional Study: researchers gather participants from different groups (commonly different ages) and look for differences between the groups. • In 1996, Russell surveyed people of varying age groups and found that people in their 20s tend to report being more lonely than people in their 70s. Correlational Design:Correlational Design: two different variables are measured to determine whether there is a relationship between them. • Thornhill et al. (2003) had people rate how physically attractive they found other people to be. They then had them separately smell t-shirts those people had worn (without knowing which clothes belonged to whom) and rate how good or bad their body oder was. They found that the more attractive someone was the more pleasant their body order was rated to be. Experiment:Experiment: researchers create a controlled environment in which they can carefully manipulate at least one variable to test its effect on another. The key here is that the researchers can cause a change in one variable. • Clinical psychologists can test a new pharmaceutical treatment for depression by giving some patients the new pill and others an already-tested one to see which is the more effective treatment. Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Modification, adaptation, and original content. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution CC licensed content, Shared previouslyCC licensed content, Shared previously • Methods for Collecting Research Data. Authored byAuthored by: Dr. Scott Roberts, Dr. Ryan Curtis, Samantha Levy, and Dr. Dylan Selterman. Provided byProvided by: University of Maryland. Located atLocated at: http://openpsyc.blogspot.com/2014/06/ methods-for-collecting-research-data.html. LicenseLicense: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike All rights reserved contentAll rights reserved content • Psychological Research - Crash Course Psychology #2. Authored byAuthored by: Hank Green. Provided byProvided by: Crash Course. Located atLocated at: https://www.youtube.com/watch?v=hFV71QPvX2I. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License DISCUSSION: RESEARCH IN PSYCHOLOGY Analyzing Research Step 1Step 1: Visit the Public Library of Science (PLOS One) website: http://journals.plos.org/plosone/browse/ psychology (a peer-reviewed journal that freely publishes research articles with open licenses). Do a search for an article that interests you, then answer the following: 1. What is the hyperlink to the study you chose? 2. What is the title of the study, and who conducted the research? 3. Describe the study in a few sentences in your own words. 4. Identify and describe either the basic assumption of the researchers, or if it was an experiment, the hypothesis. Why were they conducting this research? 5. How was the study performed? What methods were used? 6. What were the results and conclusions of this study? 7. What questions do you still have after reading about this study? For example, if you were to conduct another study based off of this study, what questions would you ask and what would you still want to find out? Step 2Step 2: Respond to at least TWO other posts in responses in a paragraph with at least 75 words. Your comments should facilitate a discussion and can highlight your own thoughts about the study. Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Discussion: Research in Psychology. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution https://creativecommons.org/licenses/by/4.0/ http://openpsyc.blogspot.com/2014/06/methods-for-collecting-research-data.html http://openpsyc.blogspot.com/2014/06/methods-for-collecting-research-data.html https://creativecommons.org/licenses/by-nc-sa/4.0/ https://www.youtube.com/watch?v=hFV71QPvX2I http://journals.plos.org/plosone/browse/psychology http://journals.plos.org/plosone/browse/psychology https://creativecommons.org/licenses/by/4.0/ MODULE 3: BIOPSYCHOLOGY WHY IT MATTERS: BIOPSYCHOLOGY Different brain imaging techniques provide scientists with insight into different aspects of how the human brain functions. Left to right, PET scan (positron emission tomography), CT scan (computed tomography), and fMRI (functional magnetic resonance imaging) are three types of scans. (credit “left”: modification of work by Health and Human Services Department, National Institutes of Health; credit “center”: modification of work by “Aceofhearts1968″/Wikimedia Commons; credit “right”: modification of work by Kim J, Matthews NL, Park S.) Have you ever taken a device apart to find out how it works? Many of us have done so, whether to attempt a repair or simply to satisfy our curiosity. A device’s internal workings are often distinct from its user interface on the outside. For example, we don’t think about microchips and circuits when we turn up the volume on a mobile phone; instead, we think about getting the volume just right. Similarly, the inner workings of the human body are often distinct from the external expression of those workings. It is the job of psychologists to find the connection between these—for example, to figure out how the firings of millions of neurons become a thought. This module strives to explain the biological mechanisms that underlie behavior. These physiological and anatomical foundations are the basis for many areas of psychology. In this module, you will learn how genetics influence both physiological and psychological traits. You will become familiar with the structure and function of the nervous system, learn how the nervous system interacts with the endocrine system, and understand the nature vs. nurture debate. AnswerAnswer Arnst, C. (2003, November). Commentary: Getting rational about health-care rationing. Bloomberg Businessweek Magazine. Retrieved from http://www.businessweek.com/stories/2003-11-16/commentary-getting-rational-about- health-care-rationing Berridge, K. C., & Robinson, T. E. (1998). What is the role of dopamine in reward: Hedonic impact, reward learning, or incentive salience? Brain Research Reviews, 28, 309–369. Chandola, T., Brunner, E., & Marmot, M. (2006). Chronic stress at work and the metabolic syndrome: A prospective study. BMJ, 332, 521–524. Comings, D. E., Gonzales, N., Saucier, G., Johnson, J. P., & MacMurray, J. P. (2000). The DRD4 gene and the spiritual transcendence scale of the character temperament index. Psychiatric Genetics, 10, 185–189. Confer, J. C., Easton, J. A., Fleischman, D. S., Goetz, C. D., Lewis, D. M. G, Perilloux, C., & Buss, D. M. (2010). Evolutionary psychology: Controversies, questions, prospects, and limitations. American Psychologist, 65, 110–126. Gaines, C. (2013, August). An A-Rod suspension would save the Yankees as much as $37.5 million in 2014 alone. Business Insider. Retrieved from http://www.businessinsider.com/an-a-rod-suspension-would-save-the- yankees-as-much-as-375-million-in-2014-2013-8 Gardner, E. L. (2011). Addiction and brain reward and antireward pathways. Advances in Psychosomatic Medicine, 30, 22–60. George, O., Le Moal, M., & Koob, G. F. (2012). Allostasis and addiction: Role of the dopamine and corticotropin- releasing factor systems. Physiology & Behavior, 106, 58–64. Glaser, R., & Kiecolt-Glaser, J. K. (2005). Stress-induced immune dysfunction: Implications for health. Nature Reviews Immunology, 5, 243–251. Gong, L., Parikh, S., Rosenthal, P. J., & Greenhouse, B. (2013). Biochemical and immunological mechanisms by which sickle cell trait protects against malaria. Malaria Journal. Advance online publication. doi:10.1186/ 1475-2875-12-317 Hardt, O., Einarsson, E. Ö., & Nader, K. (2010). A bridge over troubled water: Reconsolidation as a link between cognitive and neuroscientific memory research traditions. Annual Review of Psychology, 61, 141–167. Macmillan, M. (1999). The Phineas Gage Information Page. Retrieved from http://www.uakron.edu/gage March, J. S., Silva, S., Petrycki, S., Curry, J., Wells, K., Fairbank, J., … Severe, J. (2007). The treatment for adolescents with depression study (TADS): Long-term effectiveness and safety outcomes. Arch Gen Psychiatry, 64, 1132–1143. Mustanski, B. S., DuPree, M. G., Nievergelt, C. M., Bocklandt, S., Schork, N. J., & Hamer, D. H. (2005). A genome wide scan of male sexual orientation. Human Genetics, 116, 272–278. National Institute on Drug Abuse. (2001, July). Anabolic steroid abuse: What are the health consequences of steroid abuse? National Institutes of Health. Retrieved from http://www.drugabuse.gov/publications/research- reports/anabolic-steroid-abuse/what-are-health-consequences-steroid-abuse Squire, L. R. (2009). The legacy of patient H. M. for neuroscience. Neuron, 61, 6–9. Tienari, P., Wynne, L. C., Sorri, A., et al. (2004). Genotype–environment interaction in schizophrenia spectrum disorder: long-term follow-up study of Finnish adoptees. British Journal of Psychiatry, 184, 216–222. University of Utah Genetic Science Learning Center. (n.d.). What are genetic disorders? Retrieved from http://learn.genetics.utah.edu/content/disorders/whataregd/ Licensing & AttributionsLicensing & Attributions CC licensed content, Shared previouslyCC licensed content, Shared previously • Psychology. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@4.100:1/Psychology. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/content/col11629/latest/. http://cnx.org/contents/4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@4.100:1/Psychology https://creativecommons.org/licenses/by/4.0/ NEURAL COMMUNICATION What you’ll learn to do: identify the basic structures of a neuron, the function of each structure, and how messages travel through the neuron Neuron in tissue culture. Ever wonder how your brain actually works? What exactly is going on inside of your small, wrinkly mass while you read this text? In this section, you’ll learn about the basics of neural communication in the brain, which is the brain’s way of sending messages to and from different regions in order to relay critical information about your body and its surroundings. Glia and neurons are the two cell types that make up the nervous system. While glia generally play supporting roles, the communication between neurons is fundamental to all of the functions associated with the nervous system. Neuronal communication is made possible by the neuron’s specialized structures, like the soma, dendrites, axons, terminal buttons, and synaptic vesicles. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/11/15040629/neuron https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/11/15040629/neuron Neuronal communication is an electrochemical event. The dendrites contain receptors for neurotransmitters released by nearby neurons. If the signals received from other neurons are sufficiently strong, an action potential will travel down the length of the axon to the terminal buttons, resulting in the release of neurotransmitters into the synapse. Different neurotransmitters are associated with different functions. Often, psychological disorders involve imbalances in a given neurotransmitter system. Therefore, psychotropic drugs are prescribed in an attempt to bring the neurotransmitters back into balance. Drugs can act either as agonists or as antagonists for a given neurotransmitter system. LEARNING OBJECTIVESLEARNING OBJECTIVES • Explain the role and function of the basic structures of a neuron • Describe how neurons communicate with each other • Explain how drugs act as agonists or antagonists for a given neurotransmitter system Neurons Psychologists striving to understand the human mind may study the nervous systemnervous system. Learning how the cells and organs (like the brain) function, help us understand the biological basis behind human psychology. The nervous system is composed of two basic cell types: glial cells (also known as glia) and neurons. Glial cellsGlial cells, which outnumber neurons ten to one, are traditionally thought to play a supportive role to neurons, both physically and metabolically. Glial cells provide scaffolding on which the nervous system is built, help neurons line up closely with each other to allow neuronal communication, provide insulation to neurons, transport nutrients and waste products, and mediate immune responses. NeuronsNeurons, on the other hand, serve as interconnected information processors that are essential for all of the tasks of the nervous system. This section briefly describes the structure and function of neurons. Neuron Structure Neurons are the central building blocks of the nervous system, 100 billion strong at birth. Like all cells, neurons consist of several different parts, each serving a specialized function (Figure 1). A neuron’s outer surface is made up of a semipermeable membranesemipermeable membrane. This membrane allows smaller molecules and molecules without an electrical charge to pass through it, while stopping larger or highly charged molecules. Figure 1. This illustration shows a prototypical neuron, which is being myelinated. The nucleus of the neuron is located in the soma, or cell body. The somasoma has branching extensions known as dendritesdendrites. The neuron is a small information processor, and dendrites serve as input sites where signals are received from other neurons. These signals are transmitted electrically across the soma and down a major extension from the soma known as the axonaxon, which ends at multiple terminal buttonsterminal buttons. The terminal buttons contain synaptic vesiclessynaptic vesicles that house neurotransmittersneurotransmitters, the chemical messengers of the nervous system. Axons range in length from a fraction of an inch to several feet. In some axons, glial cells form a fatty substance known as the myelin sheathmyelin sheath, which coats the axon and acts as an insulator, increasing the speed at which the signal travels. The myelin sheath is crucial for the normal operation of the neurons within the nervous system: the loss of the insulation it provides can be detrimental to normal function. To understand how this works, let’s consider an example. Multiple sclerosis (MS), an autoimmune disorder, involves a large-scale loss of the myelin sheath on axons throughout the nervous system. The resulting interference in the electrical signal prevents the quick transmittal of information by neurons and can lead to a number of symptoms, such as dizziness, fatigue, loss of motor control, and sexual dysfunction. While some treatments may help to modify the course of the disease and manage certain symptoms, there is currently no known cure for multiple sclerosis. In healthy individuals, the neuronal signal moves rapidly down the axon to the terminal buttons, where synaptic vesicles release neurotransmitters into the synapse (Figure 2). The synapsesynapse is a very small space between two neurons and is an important site where communication between neurons occurs. Once neurotransmitters are released into the synapse, they travel across the small space and bind with corresponding receptors on the dendrite of an adjacent neuron. ReceptorsReceptors, proteins on the cell surface where neurotransmitters attach, vary in shape, with different shapes “matching” different neurotransmitters. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2031 LINK TO LEARNINGLINK TO LEARNING Click through the links at the top of this interactive simulation to review the parts of a nerve cell and to take a closer look at how neurons communicate. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2031 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2031 TRY ITTRY IT How does a neurotransmitter “know” which receptor to bind to? The neurotransmitter and the receptor have what is referred to as a lock-and-key relationship—specific neurotransmitters fit specific receptors similar to how a key fits a lock. The neurotransmitter binds to any receptor that it fits. Figure 2. (a) The synapse is the space between the terminal button of one neuron and the dendrite of another neuron. (b) In this pseudo-colored image from a scanning electron microscope, a terminal button (green) has been opened to reveal the synaptic vesicles (orange and blue) inside. Each vesicle contains about 10,000 neurotransmitter molecules. (credit b: modification of work by Tina Carvalho, NIH-NIGMS; scale-bar data from Matt Russell) https://apps.childrenshospital.org/clinical/animation/neuron/ An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2031 An interactive or media element has been excluded from this version of the text. 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You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2031 GLOSSARYGLOSSARY axon:axon: major extension of the soma dendrite:dendrite: branch-like extension of the soma that receives incoming signals from other neurons glial cell:glial cell: nervous system cell that provides physical and metabolic support to neurons, including neuronal insulation and communication, and nutrient and waste transport myelin sheath:myelin sheath: fatty substance that insulates axons neuron:neuron: cells in the nervous system that act as interconnected information processors, which are essential for all of the tasks of the nervous system neurotransmitter:neurotransmitter: chemical messenger of the nervous system receptor:receptor: protein on the cell surface where neurotransmitters attach semipermeable membrane:semipermeable membrane: cell membrane that allows smaller molecules or molecules without an electrical charge to pass through it, while stopping larger or highly charged molecules soma:soma: cell body synapse:synapse: small gap between two neurons where communication occurs synaptic vesicle:synaptic vesicle: storage site for neurotransmitters Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Modification, adaptation, and original content. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution • Addition of link to learning. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution CC licensed content, Shared previouslyCC licensed content, Shared previously • Neuron in tissue culture. Located atLocated at: https://commons.wikimedia.org/wiki/File:Neuron_in_tissue_culture . LicenseLicense: CC BY-SA: Attribution-ShareAlike • Cells of the Nervous System. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.52:SO2ufnKm@7/Cells-of-the-Nervous-System. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/contents/4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@5.48 All rights reserved contentAll rights reserved content • 2-Minute Neuroscience: The Neuron. Authored byAuthored by: Neuroscientifically Challenged. Located atLocated at: https://www.youtube.com/watch?v=6qS83wD29PY. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://commons.wikimedia.org/wiki/File:Neuron_in_tissue_culture https://creativecommons.org/licenses/by-sa/4.0/ http://cnx.org/contents/Sr8Ev5Og@5.52:SO2ufnKm@7/Cells-of-the-Nervous-System https://creativecommons.org/licenses/by/4.0/ https://www.youtube.com/watch?v=6qS83wD29PY THE NERVOUS SYSTEM AND ENDOCRINE SYSTEM What you’ll learn to do: describe the role of the nervous system and endocrine systems In this section, you’ll learn about the basics of the central nervous system, which consists of the brain and spinal cord, as well as the peripheral nervous system. The peripheral nervous systemperipheral nervous system is comprised of the somatic and autonomic nervous systems. The somaticsomatic nervous systemnervous system transmits sensory and motor signals to and from the central nervous system. The autonomicautonomic nervous systemnervous system controls the function of our organs and glands, and can be divided into the sympathetic and parasympathetic divisions. SympatheticSympathetic activation prepares us for fight or flight, while parasympatheticparasympathetic activation is associated with normal functioning under relaxed conditions. The endocrineendocrine systemsystem consists of a series of glands that produce chemical substances known as hormones, which produce widespread effects on the body. Got all that? We’ll review each of these systems in the coming pages. Visit this course online to take this short practice quiz: https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/11/15233230/Blausen_0822_SpinalCord LEARNING OBJECTIVESLEARNING OBJECTIVES • Describe the difference between the central and peripheral nervous systems and the somatic and autonomic nervous systems • Differentiate between the sympathetic and parasympathetic divisions of the autonomic nervous system • Describe the endocrine system and explain its primary responsibilities within the body The Central Nervous System and the Peripheral Nervous System The nervous systemnervous system can be divided into two major subdivisions: the central nervous system (CNS)central nervous system (CNS) and the peripheral nervous system (PNS)peripheral nervous system (PNS), shown in Figure 1. The CNS is comprised of the brain and spinal cord; the PNS connects the CNS to the rest of the body. In this section, we focus on the peripheral nervous system; later, we look at the brain and spinal cord. Figure 1. The nervous system is divided into two major parts: (a) the Central Nervous System and (b) the Peripheral Nervous System. Peripheral Nervous System The peripheral nervous system is made up of thick bundles of axons, called nerves, carrying messages back and forth between the CNS and the muscles, organs, and senses in the periphery of the body (i.e., everything outside the CNS). The PNS has two major subdivisions: the somatic nervous system and the autonomic nervous system. The somatic nervous systemsomatic nervous system is associated with activities traditionally thought of as conscious or voluntary. It is involved in the relay of sensory and motor information to and from the CNS; therefore, it consists of motor neurons and sensory neurons. Motor neurons, carrying instructions from the CNS to the muscles, are efferent fibers (efferent means “moving away from”). Sensory neurons, carrying sensory information to the CNS, are afferent fibers (afferent means “moving toward”). Each nerve is basically a two-way superhighway, containing thousands of axons, both efferent and afferent. The autonomic nervous systemautonomic nervous system controls our internal organs and glands and is generally considered to be outside the realm of voluntary control. It can be further subdivided into the sympathetic and parasympathetic divisions (Figure 2). The sympathetic nervous systemsympathetic nervous system is involved in preparing the body for stress-related activities; the parasympathetic nervous systemparasympathetic nervous system is associated with returning the body to routine, day-to-day operations. The two systems have complementary functions, operating in tandem to maintain the body’s homeostasis. HomeostasisHomeostasis is a state of equilibrium, in which biological conditions (such as body temperature) are maintained at optimal levels. Figure 2. The sympathetic and parasympathetic divisions of the autonomic nervous system have the opposite effects on various systems. The sympathetic nervous system is activated when we are faced with stressful or high-arousal situations. The activity of this system was adaptive for our ancestors, increasing their chances of survival. Imagine, for example, that one of our early ancestors, out hunting small game, suddenly disturbs a large bear with her cubs. At that moment, his body undergoes a series of changes—a direct function of sympathetic activation—preparing him to face the threat. His pupils dilate, his heart rate and blood pressure increase, his bladder relaxes, his liver releases glucose, and adrenaline surges into his bloodstream. This constellation of physiological changes, known as the fight or flight responsefight or flight response, allows the body access to energy reserves and heightened sensory capacity so that it might fight off a threat or run away to safety. LINK TO LEARNINGLINK TO LEARNING Reinforce what you’ve learned about the nervous system by playing this BBC-produced interactive game about the nervous system. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=106 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=106 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=106 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=106 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=106 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=106 TRY ITTRY IT While it is clear that such a response would be critical for survival for our ancestors, who lived in a world full of real physical threats, many of the high-arousal situations we face in the modern world are more psychological in nature. For example, think about how you feel when you have to stand up and give a presentation in front of a roomful of people, or right before taking a big test. You are in no real physical danger in those situations, and yet you have evolved to respond to any perceived threat with the fight or flight response. This kind of response is not nearly as adaptive in the modern world; in fact, we suffer negative health consequences when faced constantly with psychological threats that we can neither fight nor flee. Recent research suggests that an increase in susceptibility to heart disease (Chandola, Brunner, & Marmot, 2006) and impaired function of the immune system (Glaser & Kiecolt-Glaser, 2005) are among the many negative consequences of persistent and repeated exposure to stressful situations. Once the threat has been resolved, the parasympathetic nervous system takes over and returns bodily functions to a relaxed state. Our hunter’s heart rate and blood pressure return to normal, his pupils constrict, he regains control of his bladder, and the liver begins to store glucose in the form of glycogen for future use. These processes are associated with activation of the parasympathetic nervous system. https://www.bbc.co.uk/science/humanbody/body/interactives/3djigsaw_02/index.shtml?nervous An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=106 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=106 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=106 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=106 THINK IT OVERTHINK IT OVER Hopefully, you do not face real physical threats from potential predators on a daily basis. However, you probably have your fair share of stress. What situations are your most common sources of stress? What can you do to try to minimize the negative consequences of these particular stressors in your life? The Endocrine System The endocrine systemendocrine system consists of a series of glands that produce chemical substances known as hormoneshormones (Figure 1). Like neurotransmitters, hormones are chemical messengers that must bind to a receptor in order to send their signal. However, unlike neurotransmitters, which are released in close proximity to cells with their receptors, hormones are secreted into the bloodstream and travel throughout the body, affecting any cells that contain receptors for them. Thus, whereas neurotransmitters’ effects are localized, the effects of hormones are widespread. Also, hormones are slower to take effect, and tend to be longer lasting. Figure 3. The major glands of the endocrine system are shown. The study of psychology and the endocrine system is called behavioral endocrinology, which is the scientific study of the interaction between hormones and behavior. This interaction is bidirectional: hormones can influence behavior, and behavior can sometimes influence hormone concentrations. Hormones regulate behaviors such as aggression, mating, and parenting of individuals. Hormones are involved in regulating all sorts of bodily functions, and they are ultimately controlled through interactions between the hypothalamus (in the central nervous system) and the pituitary gland (in the endocrine system). Imbalances in hormones are related to a number of disorders. This section explores some of the major glands that make up the endocrine system and the hormones secreted by these glands. Major Glands The pituitary glandpituitary gland descends from the hypothalamus at the base of the brain, and acts in close association with it. The pituitary is often referred to as the “master gland” because its messenger hormones control all the other glands in the endocrine system, although it mostly carries out instructions from the hypothalamus. In addition to An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=106 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=106 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=106 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=106 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=106 TRY ITTRY IT messenger hormones, the pituitary also secretes growth hormone, endorphins for pain relief, and a number of key hormones that regulate fluid levels in the body. Located in the neck, the thyroid glandthyroid gland releases hormones that regulate growth, metabolism, and appetite. In hyperthyroidism, or Grave’s disease, the thyroid secretes too much of the hormone thyroxine, causing agitation, bulging eyes, and weight loss. In hypothyroidism, reduced hormone levels cause sufferers to experience tiredness, and they often complain of feeling cold. Fortunately, thyroid disorders are often treatable with medications that help reestablish a balance in the hormones secreted by the thyroid. The adrenal glandsadrenal glands sit atop our kidneys and secrete hormones involved in the stress response, such as epinephrine (adrenaline) and norepinephrine (noradrenaline). The pancreaspancreas is an internal organ that secretes hormones that regulate blood sugar levels: insulin and glucagon. These pancreatic hormones are essential for maintaining stable levels of blood sugar throughout the day by lowering blood glucose levels (insulin) or raising them (glucagon). People who suffer from diabetesdiabetes do not produce enough insulin; therefore, they must take medications that stimulate or replace insulin production, and they must closely control the amount of sugars and carbohydrates they consume. The gonadsgonads secrete sexual hormones, which are important in reproduction, and mediate both sexual motivation and behavior. The female gonads are the ovaries; the male gonads are the testis. Ovaries secrete estrogens and progesterone, and the testes secrete androgens, such as testosterone. DIG DEEPER: ATHLETES AND ANABOLIC STEROIDSDIG DEEPER: ATHLETES AND ANABOLIC STEROIDS Although it is against most laws to do so, many professional athletes and body builders use anabolic steroid drugs to improve their athletic performance and physique. Anabolic steroid drugs mimic the effects of the body’s own steroid hormones, like testosterone and its derivatives. These drugs have the potential to provide a competitive edge by increasing muscle mass, strength, and endurance, although not all users may experience these results. Moreover, use of performance-enhancing drugs (PEDs) does not come without risks. Anabolic steroid use has been linked with a wide variety of potentially negative outcomes, ranging in severity from largely cosmetic (acne) to life threatening (heart attack). Furthermore, use of these substances can result in profound changes in mood and can increase aggressive behavior (National Institute on Drug Abuse, 2001). Baseball player Alex Rodriguez (A-Rod) has been at the center of a media storm regarding his use of illegal PEDs. Rodriguez’s performance on the field was unparalleled while using the drugs; his success played a large role in negotiating a contract that made him the highest paid player in professional baseball. Although Rodriguez maintains that he has not used PEDs for the several years, he received a substantial suspension in 2013 that, if upheld, will cost him more than 20 million dollars in earnings (Gaines, 2013). What are your thoughts on athletes and doping? Why or why not should the use of PEDs be banned? What advice would you give an athlete who was considering using PEDs? LINK TO LEARNINGLINK TO LEARNING Learn more about endocrinology from The Noba Psychology article, “Hormones and Behavior.” Hormones and Behavior How might behaviors affect hormones? Extensive studies on male zebra finches and their singing (only males finches sing) demonstrate that the hormones testosterone and estradiol affect their singing, but the reciprocal relation also occurs; that is, behavior can affect hormone concentrations. For example, the sight of a territorial intruder may elevate blood testosterone concentrations in resident male birds and thereby stimulate singing or fighting behavior. Similarly, male mice or rhesus monkeys that lose a fight decrease circulating testosterone concentrations for several days or even weeks afterward. Comparable results have also been reported in humans. Testosterone concentrations are affected not only in humans involved in physical combat, but also in those involved in simulated battles. For example, testosterone concentrations were elevated in winners and reduced in losers of regional chess tournaments. People do not have to be directly involved in a contest to have their hormones affected by the outcome of the contest. Male fans of both the Brazilian and Italian teams were recruited to provide saliva samples to be assayed for testosterone before and after the final game of the World Cup soccer match in 1994. Brazil and Italy were tied going into the final game, but Brazil won on a penalty kick at the last possible moment. The Brazilian fans were elated and the Italian fans were crestfallen. When the samples were assayed, 11 of 12 Brazilian fans who were sampled had increased testosterone concentrations, and 9 of 9 Italian fans had decreased testosterone concentrations, compared with pre-game baseline values (Dabbs, 2000). In some cases, hormones can be affected by anticipation of behavior. For example, testosterone concentrations also influence sexual motivation and behavior in women. In one study, the interaction between sexual intercourse and testosterone was compared with other activities (cuddling or exercise) in women (van Anders, Hamilton, Schmidt, & Watson, 2007). On three separate occasions, women provided a pre-activity, post-activity, and next- morning saliva sample. After analysis, the women’s testosterone was determined to be elevated prior to intercourse as compared to other times. Thus, an anticipatory relationship exists between sexual behavior and testosterone. Testosterone values were higher post-intercourse compared to exercise, suggesting that engaging in sexual behavior may also influence hormone concentrations in women. http://nobaproject.com/textbooks/wendy-king-introduction-to-psychology-the-full-noba-collection/modules/hormones-behavior An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=106 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=106 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=106 TRY ITTRY IT GLOSSARYGLOSSARY adrenal gland:adrenal gland: sits atop our kidneys and secretes hormones involved in the stress response autonomic nervous system:autonomic nervous system: controls our internal organs and glands central nervous system (CNS):central nervous system (CNS): brain and spinal cord diabetes:diabetes: disease related to insufficient insulin production endocrine system:endocrine system: series of glands that produce chemical substances known as hormones fight or flight response:fight or flight response: activation of the sympathetic division of the autonomic nervous system, allowing access to energy reserves and heightened sensory capacity so that we might fight off a given threat or run away to safety gonad:gonad: secretes sexual hormones, which are important for successful reproduction, and mediate both sexual motivation and behavior homeostasis:homeostasis: state of equilibrium—biological conditions, such as body temperature, are maintained at optimal levels hormone:hormone: chemical messenger released by endocrine glands pancreas:pancreas: secretes hormones that regulate blood sugar parasympathetic nervous system:parasympathetic nervous system: associated with routine, day-to-day operations of the body peripheral nervous system (PNS):peripheral nervous system (PNS): connects the brain and spinal cord to the muscles, organs and senses in the periphery of the body pituitary gland:pituitary gland: secretes a number of key hormones, which regulate fluid levels in the body, and a number of messenger hormones, which direct the activity of other glands in the endocrine system thyroid:thyroid: secretes hormones that regulate growth, metabolism, and appetite somatic nervous system:somatic nervous system: relays sensory and motor information to and from the CNS sympathetic nervous system:sympathetic nervous system: involved in stress-related activities and functions THINK IT OVERTHINK IT OVER Given the negative health consequences associated with the use of anabolic steroids, what kinds of considerations might be involved in a person’s decision to use them? An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=106 Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Modification, adaptation, and original content. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution CC licensed content, Shared previouslyCC licensed content, Shared previously • The Endocrine System. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.49:34oFmAxl@6/The-Endocrine-System. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/content/col11629/latest/. • Hormones and Behavior and introductory section and part on endocrinology. Authored byAuthored by: Randy J. Nelson. Provided byProvided by: The Ohio State University. Located atLocated at: http://nobaproject.com/textbooks/wendy-king- introduction-to-psychology-the-full-noba-collection/modules/hormones-behavior. ProjectProject: The Noba Project. LicenseLicense: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike • Parts of the Nervous System. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.52:-xs7Ve8V@6/Parts-of-the-Nervous-System. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/contents/4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@5.48 Public domain contentPublic domain content • Spinal Cord. Authored byAuthored by: BruceBlaus. Provided byProvided by: Wikimedia. Located atLocated at: https://en.wikipedia.org/wiki/Surfer%27s_myelopathy#/media/File:Blausen_0822_SpinalCord . LicenseLicense: CC BY: Attribution PARTS OF THE BRAIN What you’ll learn to do: identify and describe the parts of the brain In this section, you’ll learn about the specific parts of the brain and their roles and functions. While this is not an anatomy class, you’ll see how important it is to understand the parts of the brain and what they do so that we can understand mental processes and behavior. Watch this CrashCourse Psychology video for an overview on the brain and the interesting topics we’ll cover: https://creativecommons.org/licenses/by/4.0/ http://cnx.org/contents/Sr8Ev5Og@5.49:34oFmAxl@6/The-Endocrine-System https://creativecommons.org/licenses/by/4.0/ http://nobaproject.com/textbooks/wendy-king-introduction-to-psychology-the-full-noba-collection/modules/hormones-behavior http://nobaproject.com/textbooks/wendy-king-introduction-to-psychology-the-full-noba-collection/modules/hormones-behavior https://creativecommons.org/licenses/by-nc-sa/4.0/ http://cnx.org/contents/Sr8Ev5Og@5.52:-xs7Ve8V@6/Parts-of-the-Nervous-System https://creativecommons.org/licenses/by/4.0/ https://en.wikipedia.org/wiki/Surfer%27s_myelopathy#/media/File:Blausen_0822_SpinalCord https://creativecommons.org/licenses/by/4.0/ https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/11/15045703/brainlobes A YouTube element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2036 LEARNING OBJECTIVESLEARNING OBJECTIVES • Explain the two hemispheres of the brain, lateralization and plasticity • Identify the location and function of the lobes of the brain The Central Nervous System The central nervous system (CNS), consists of the brain and the spinal cord. The Brain The brain is a remarkably complex organ comprised of billions of interconnected neurons and glia. It is a bilateral, or two-sided, structure that can be separated into distinct lobes. Each lobe is associated with certain types of functions, but, ultimately, all of the areas of the brain interact with one another to provide the foundation for our thoughts and behaviors. The Spinal Cord It can be said that the spinal cord is what connects the brain to the outside world. Because of it, the brain can act. The spinal cord is like a relay station, but a very smart one. It not only routes messages to and from the brain, but it also has its own system of automatic processes, called reflexes. Figure 1. The surface of the brain is covered with gyri and sulci. A deep sulcus is called a fissure, such as the longitudinal fissure that divides the brain into left and right hemispheres. (credit: modification of work by Bruce Blaus) The top of the spinal cord merges with the brain stem, where the basic processes of life are controlled, such as breathing and digestion. In the opposite direction, the spinal cord ends just below the ribs—contrary to what we might expect, it does not extend all the way to the base of the spine. The spinal cord is functionally organized in 30 segments, corresponding with the vertebrae. Each segment is connected to a specific part of the body through the peripheral nervous system. Nerves branch out from the spine at each vertebra. Sensory nerves bring messages in; motor nerves send messages out to the muscles and organs. Messages travel to and from the brain through every segment. Some sensory messages are immediately acted on by the spinal cord, without any input from the brain. Withdrawal from heat and knee jerk are two examples. When a sensory message meets certain parameters, the spinal cord initiates an automatic reflex. The signal passes from the sensory nerve to a simple processing center, which initiates a motor command. Seconds are saved, because messages don’t have to go the brain, be processed, and get sent back. In matters of survival, the spinal reflexes allow the body to react extraordinarily fast. The spinal cord is protected by bony vertebrae and cushioned in cerebrospinal fluid, but injuries still occur. When the spinal cord is damaged in a particular segment, all lower segments are cut off from the brain, causing paralysis. Therefore, the lower on the spine damage is, the fewer functions an injured individual loses. The Two Hemispheres The surface of the brain, known as the cerebral cortexcerebral cortex, is very uneven, characterized by a distinctive pattern of folds or bumps, known as gyrigyri (singular: gyrus), and grooves, known as sulcisulci (singular: sulcus), shown in Figure 1. These gyri and sulci form important landmarks that allow us to separate the brain into functional centers. The most prominent sulcus, known as the longitudinal fissure, is the deep groove that separates the brain into two halves or hemispheres: the left hemisphere and the right hemisphere. There is evidence of some specialization of function—referred to as lateralizationlateralization—in each hemisphere, mainly regarding differences in language ability. Beyond that, however, the differences that have been found have been minor. What we do know is that the left hemisphere controls the right half of the body, and the right hemisphere controls the left half of the body. The two hemispheres are connected by a thick band of neural fibers known as the corpus callosumcorpus callosum, consisting of about 200 million axons. The corpus callosum allows the two hemispheres to communicate with each other and allows for information being processed on one side of the brain to be shared with the other side. Normally, we are not aware of the different roles that our two hemispheres play in day-to-day functions, but there are people who come to know the capabilities and functions of their two hemispheres quite well. In some cases of severe epilepsy, doctors elect to sever the corpus callosum as a means of controlling the spread of seizures (Figure 2). While this is an effective treatment option, it results in individuals who have split brains. After surgery, these split-brain patients show a variety of interesting behaviors. For instance, a split-brain patient is unable to name a picture that is shown in the patient’s left visual field because the information is only available in the largely nonverbal right hemisphere. However, they are able to recreate the picture with their left hand, which is also controlled by the right hemisphere. When the more verbal left hemisphere sees the picture that the hand drew, the patient is able to name it (assuming the left hemisphere can interpret what was drawn by the left hand). Figure 2. (a, b) The corpus callosum connects the left and right hemispheres of the brain. (c) A scientist spreads this dissected sheep brain apart to show the corpus callosum between the hemispheres. (credit c: modification of work by Aaron Bornstein) LINK TO LEARNINGLINK TO LEARNING This interactive animation from the Nobel Prize website walks users through the hemispheres of the brain. LINK TO LEARNINGLINK TO LEARNING Watch this video to see an incredible example of the challenges facing a split-brain patient shortly following the surgery to sever her corpus callosum. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2036 TRY ITTRY IT Much of what we know about the functions of different areas of the brain comes from studying changes in the behavior and ability of individuals who have suffered damage to the brain. For example, researchers study the behavioral changes caused by strokes to learn about the functions of specific brain areas. A stroke, caused by an interruption of blood flow to a region in the brain, causes a loss of brain function in the affected region. The damage can be in a small area, and, if it is, this gives researchers the opportunity to link any resulting behavioral changes to a specific area. The types of deficits displayed after a stroke will be largely dependent on where in the brain the damage occurred. Consider Theona, an intelligent, self-sufficient woman, who is 62 years old. Recently, she suffered a stroke in the front portion of her right hemisphere. As a result, she has great difficulty moving her left leg. (As you learned earlier, the right hemisphere controls the left side of the body; also, the brain’s main motor centers are located at the front of the head, in the frontal lobe.) Theona has also experienced behavioral changes. For example, while in the produce section of the grocery store, she sometimes eats grapes, strawberries, and apples directly from their bins before paying for them. This behavior—which would have been very embarrassing to her before the stroke—is consistent with damage in another region in the frontal lobe—the prefrontal cortex, which is associated with judgment, reasoning, and impulse control. http://www.nobelprize.org/educational/medicine/split-brain/splitbrainexp.html https://educationalgames.nobelprize.org/educational/medicine/split-brain/ A YouTube element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2036 Watch this second about another patient who underwent a dramatic surgery to prevent her seizures. You’ll learn more about the brain’s ability to change, adapt, and reorganize itself, also known as brain plasticityplasticity. A YouTube element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2036 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2036 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2036 Forebrain Structures The two hemispheres of the cerebral cortex are part of the forebrainforebrain (Figure 3), which is the largest part of the brain. The forebrain contains the cerebral cortex and a number of other structures that lie beneath the cortex (called subcortical structures): thalamus, hypothalamus, pituitary gland, and the limbic system (collection of structures). The cerebral cortex, which is the outer surface of the brain, is associated with higher level processes such as consciousness, thought, emotion, reasoning, language, and memory. Each cerebral hemisphere can be subdivided into four lobes, each associated with different functions. Figure 3. The brain and its parts can be divided into three main categories: the forebrain, midbrain, and hindbrain. Lobes of the Brain The four lobes of the brain are the frontal, parietal, temporal, and occipital lobes (Figure 4). The frontal lobefrontal lobe is located in the forward part of the brain, extending back to a fissure known as the central sulcus. The frontal lobe is involved in reasoning, motor control, emotion, and language. It contains the motor cortexmotor cortex, which is involved in planning and coordinating movement; the prefrontal cortexprefrontal cortex, which is responsible for higher-level cognitive functioning; and Broca’s areaBroca’s area, which is essential for language production. Figure 4. The lobes of the brain are shown. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2036 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2036 TRY ITTRY IT People who suffer damage to Broca’s area have great difficulty producing language of any form. For example, Padma was an electrical engineer who was socially active and a caring, involved mother. About twenty years ago, she was in a car accident and suffered damage to her Broca’s area. She completely lost the ability to speak and form any kind of meaningful language. There is nothing wrong with her mouth or her vocal cords, but she is unable to produce words. She can follow directions but can’t respond verbally, and she can read but no longer write. She can do routine tasks like running to the market to buy milk, but she could not communicate verbally if a situation called for it. Probably the most famous case of frontal lobe damage is that of a man by the name of Phineas Gage. On September 13, 1848, Gage (age 25) was working as a railroad foreman in Vermont. He and his crew were using an iron rod to tamp explosives down into a blasting hole to remove rock along the railway’s path. Unfortunately, the iron rod created a spark and caused the rod to explode out of the blasting hole, into Gage’s face, and through his skull (Figure 5). Although lying in a pool of his own blood with brain matter emerging from his head, Gage was conscious and able to get up, walk, and speak. But in the months following his accident, people noticed that his personality had changed. Many of his friends described him as no longer being himself. Before the accident, it was said that Gage was a well-mannered, soft-spoken man, but he began to behave in odd and inappropriate ways after the accident. Such changes in personality would be consistent with loss of impulse control—a frontal lobe function. Beyond the damage to the frontal lobe itself, subsequent investigations into the rod’s path also identified probable damage to pathways between the frontal lobe and other brain structures, including the limbic system. With connections between the planning functions of the frontal lobe and the emotional processes of the limbic system severed, Gage had difficulty controlling his emotional impulses. However, there is some evidence suggesting that the dramatic changes in Gage’s personality were exaggerated and embellished. Gage’s case occurred in the midst of a 19th century debate over localization—regarding whether certain areas of the brain are associated with particular functions. On the basis of extremely limited information about Gage, the extent of his injury, and his life before and after the accident, scientists tended to find support for their own views, on whichever side of the debate they fell (Macmillan, 1999). Figure 5. (a) Phineas Gage holds the iron rod that penetrated his skull in an 1848 railroad construction accident. (b) Gage’s prefrontal cortex was severely damaged in the left hemisphere. The rod entered Gage’s face on the left side, passed behind his eye, and exited through the top of his skull, before landing about 80 feet away. (credit a: modification of work by Jack and Beverly Wilgus) A YouTube element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2036 LINK TO LEARNINGLINK TO LEARNING Watch either (or both) clip(s) about Phineas Gage to learn more about his accident and injury. A YouTube element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2036 Figure 6: Specific body parts like the tongue or fingers are mapped onto certain areas of the brain including the primary motor cortex. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/01/20221528/motorcortex https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/01/20221528/motorcortex Figure 7. Spatial relationships in the body are mirrored in the organization of the somatosensory cortex. Figure 8. Damage to either Broca’s area or Wernicke’s area can result in language deficits. The types of deficits are very different, however, depending on which area is affected. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2036 TRY ITTRY IT One particularly fascinating area in the frontal lobe is called the “primary motor cortex”. This strip running along the side of the brain is in charge of voluntary movements like waving goodbye, wiggling your eyebrows, and kissing. It is an excellent example of the way that the various regions of the brain are highly specialized. Interestingly, each of our various body parts has a unique portion of the primary motor cortex devoted to it (see Figure 6). Each individual finger has about as much dedicated brain space as your entire leg. Your lips, in turn, require about as much dedicated brain processing as all of your fingers and your hand combined! Because the cerebral cortex in general, and the frontal lobe in particular, are associated with such sophisticated functions as planning and being self-aware they are often thought of as a higher, less primal portion of the brain. Indeed, other animals such as rats and kangaroos while they do have frontal regions of their brain do not have the same level of development in the cerebral cortices. The closer an animal is to humans on the evolutionary tree—think chimpanzees and gorillas, the more developed is this portion of their brain. The brain’s parietal lobeparietal lobe is located immediately behind the frontal lobe, and is involved in processing information from the body’s senses. It contains the somatosensory cortexsomatosensory cortex, which is essential for processing sensory information from across the body, such as touch, temperature, and pain. The somatosensory cortex is organized topographically, which means that spatial relationships that exist in the body are maintained on the surface of the somatosensory cortex. For example, the portion of the cortex that processes sensory information from the hand is adjacent to the portion that processes information from the wrist. The temporal lobetemporal lobe is located on the side of the head (temporal means “near the temples”), and is associated with hearing, memory, emotion, and some aspects of language. The auditory cortexauditory cortex, the main area responsible for processing auditory information, is located within the temporal lobe. Wernicke’s areaWernicke’s area, important for speech comprehension, is also located here. Whereas individuals with damage to Broca’s area have difficulty producing language, those with damage to Wernicke’s area can produce sensible language, but they are unable to understand it (Figure 8). The occipital lobeoccipital lobe is located at the very back of the brain, and contains the primary visual cortex, which is responsible for interpreting incoming visual information. The occipital cortex is organized retinotopically, which means there is a close relationship between the position of an object in a person’s visual field and the position of that object’s representation on the cortex. You will learn much more about how visual information is processed in the occipital lobe when you study sensation and perception. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2036 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2036 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2036 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2036 FOOD FOR THOUGHTFOOD FOR THOUGHT Consider the following advice from Joseph LeDoux, a professor of neuroscience and psychology at New York University, as you learn about the specific parts of the brain: Be suspicious of any statement that says a brain area is a center responsible for some function. The notion of functions being products of brain areas or centers is left over from the days when most evidence about brain function was based on the effects of brain lesions localized to specific areas. Today, we think of functions as products of systems rather than of areas. Neurons in areas contribute because they are part of a system. The amygdala, for example, contributes to threat detection because it is part of a threat detection system. And just because the amygdala contributes to threat detection does not mean that threat detection is the only function to which it contributes. Amygdala neurons, for example, are also components of systems that process the significance of stimuli related to eating, drinking, sex, and addictive drugs. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2036 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2036 TRY ITTRY IT An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2036 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2036 GLOSSARYGLOSSARY auditory cortex:auditory cortex: strip of cortex in the temporal lobe that is responsible for processing auditory information Broca’s area:Broca’s area: region in the left hemisphere that is essential for language production cerebral cortex:cerebral cortex: surface of the brain that is associated with our highest mental capabilities corpus callosum:corpus callosum: thick band of neural fibers connecting the brain’s two hemispheres forebrain:forebrain: largest part of the brain, containing the cerebral cortex, the thalamus, and the limbic system, among other structures frontal lobe:frontal lobe: part of the cerebral cortex involved in reasoning, motor control, emotion, and language; contains motor cortex gyrusgyrus (plural: gyri): bump or ridge on the cerebral cortex hemisphere:hemisphere: left or right half of the brain lateralization:lateralization: concept that each hemisphere of the brain is associated with specialized functions longitudinal fissure:longitudinal fissure: deep groove in the brain’s cortex motor cortex:motor cortex: strip of cortex involved in planning and coordinating movement occipital lobe:occipital lobe: part of the cerebral cortex associated with visual processing; contains the primary visual cortex parietal lobe:parietal lobe: part of the cerebral cortex involved in processing various sensory and perceptual information; contains the primary somatosensory cortex prefrontal cortex:prefrontal cortex: area in the frontal lobe responsible for higher-level cognitive functioning somatosensory cortex:somatosensory cortex: essential for processing sensory information from across the body, such as touch, temperature, and pain sulcussulcus (plural: sulci): depressions or grooves in the cerebral cortex temporal lobe:temporal lobe: part of cerebral cortex associated with hearing, memory, emotion, and some aspects of language; contains primary auditory cortex Wernicke’s area:Wernicke’s area: important for speech comprehension Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Introduction. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution CC licensed content, Shared previouslyCC licensed content, Shared previously • The Brain and Spinal Cord. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.49:_Io4zP0c@7/The-Brain-and-Spinal-Cord. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/content/col11629/latest/. • Modification, adaptation, and original content. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution • The Amygdala Is Not The Brains Fear Center. Authored byAuthored by: Joseph LeDoux. Located atLocated at: http://thepsychreport.com/science/the-amygdala-is-not-the-brains-fear-center/. ProjectProject: The Psych Report. LicenseLicense: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike • Motor cortex paragraphs and image. Authored byAuthored by: Robert Biswas-Diener. Provided byProvided by: Portland State University. Located atLocated at: http://nobaproject.com/modules/the-brain-and-nervous-system. ProjectProject: The Noba Project. LicenseLicense: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike All rights reserved contentAll rights reserved content • Meet Your Master: Getting to Know Your Brain - Crash Course Psychology #4. Provided byProvided by: CrashCourse . Located atLocated at: https://www.youtube.com/watch?v=vHrmiy4W9C0. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License • Split Brain mpeg1video. Authored byAuthored by: mrsrooboy. Located atLocated at: https://www.youtube.com/watch?v=8C8qu8FnuAo&feature=youtu.be. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License • Brain Plasticity - the story of Jody. Authored byAuthored by: Streetwisdom Billy. Located atLocated at: https://www.youtube.com/watch?v=VaDlLD97CLM&feature=youtu.be. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License • Phineas Gage (LEGO Stop-Motion Music Video). Authored byAuthored by: Brad Wray. Located atLocated at: https://www.youtube.com/watch?v=_nikOxNfjqs. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License Public domain contentPublic domain content • brain image. Authored byAuthored by: Henry Gray. Provided byProvided by: Wikimedia. Located atLocated at: https://commons.wikimedia.org/wiki/File:Lobes_of_the_brain_NL.svg. LicenseLicense: Public Domain: No Known Copyright https://creativecommons.org/licenses/by/4.0/ http://cnx.org/contents/Sr8Ev5Og@5.49:_Io4zP0c@7/The-Brain-and-Spinal-Cord https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ http://thepsychreport.com/science/the-amygdala-is-not-the-brains-fear-center/ https://creativecommons.org/licenses/by-nc-sa/4.0/ https://creativecommons.org/licenses/by-nc-sa/4.0/ http://nobaproject.com/modules/the-brain-and-nervous-system https://creativecommons.org/licenses/by-nc-sa/4.0/ https://www.youtube.com/watch?v=vHrmiy4W9C0 https://www.youtube.com/watch?v=8C8qu8FnuAo&feature=youtu.be https://www.youtube.com/watch?v=VaDlLD97CLM&feature=youtu.be https://www.youtube.com/watch?v=_nikOxNfjqs https://commons.wikimedia.org/wiki/File:Lobes_of_the_brain_NL.svg https://creativecommons.org/about/pdm THE LIMBIC SYSTEM AND OTHER BRAIN AREAS LEARNING OBJECTIVESLEARNING OBJECTIVES • Identify and describe the role of the parts of the limbic system, the midbrain, and hindbrain Areas of the Forebrain Other areas of the forebrainforebrain (which includes the lobes that you learned about previously), are the parts located beneath the cerebral cortex, including the thalamus and the limbic system. The thalamusthalamus is a sensory relay for the brain. All of our senses, with the exception of smell, are routed through the thalamus before being directed to other areas of the brain for processing (Figure 1). Figure 1. The thalamus serves as the relay center of the brain where most senses are routed for processing. The limbic systemlimbic system is involved in processing both emotion and memory. Interestingly, the sense of smell projects directly to the limbic system; therefore, not surprisingly, smell can evoke emotional responses in ways that other sensory modalities cannot. The limbic system is made up of a number of different structures, but three of the most important are the hippocampus, the amygdala, and the hypothalamus (Figure 2). The hippocampushippocampus is an essential structure for learning and memory. The amygdalaamygdala is involved in our experience of emotion and in tying emotional meaning to our memories. The hypothalamushypothalamus regulates a number of homeostatic processes, including the regulation of body temperature, appetite, and blood pressure. The hypothalamus also serves as an interface between the nervous system and the endocrine system and in the regulation of sexual motivation and behavior. Figure 2. The limbic system is involved in mediating emotional response and memory. THE CASE OF HENRY MOLAISON (H.M.)THE CASE OF HENRY MOLAISON (H.M.) In 1953, Henry Gustav Molaison (H. M.) was a 27-year-old man who experienced severe seizures. In an attempt to control his seizures, H. M. underwent brain surgery to remove his hippocampus and amygdala. Following the surgery, H.M’s seizures became much less severe, but he also suffered some unexpected—and devastating—consequences of the surgery: he lost his ability to form many types of new memories. For example, he was unable to learn new facts, such as who was president of the United States. He was able to learn new skills, but afterward he had no recollection of learning them. For example, while he might learn to use a computer, he would have no conscious memory of ever having used one. He could not remember new faces, and he was unable to remember events, even immediately after they occurred. Researchers were fascinated by his experience, and he is considered one of the most studied cases in medical and psychological history (Hardt, Einarsson, & Nader, 2010; Squire, 2009). Indeed, his case has provided tremendous insight into the role that the hippocampus plays in the consolidation of new learning into explicit memory. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=1999 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=1999 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=1999 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=1999 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=1999 TRY ITTRY IT LINK TO LEARNINGLINK TO LEARNING Clive Wearing, an accomplished musician, lost the ability to form new memories when his hippocampus was damaged through illness. Check out the first few minutes of this documentary video for an introduction to this man and his condition. Midbrain and Hindbrain Structures The midbrainmidbrain is comprised of structures located deep within the brain, between the forebrain and the hindbrain. The reticular formationreticular formation is centered in the midbrain, but it actually extends up into the forebrain and down into the hindbrain. The reticular formation is important in regulating the sleep/wake cycle, arousal, alertness, and motor activity. The substantia nigrasubstantia nigra (Latin for “black substance”) and the ventral tegmental area (VTA)ventral tegmental area (VTA) are also located in the midbrain (Figure 3). Both regions contain cell bodies that produce the neurotransmitter dopamine, and both are critical for movement. Degeneration of the substantia nigra and VTA is involved in Parkinson’s disease. In addition, these structures are involved in mood, reward, and addiction (Berridge & Robinson, 1998; Gardner, 2011; George, Le Moal, & Koob, 2012). https://www.youtube.com/watch?v=ipD_G7U2FcM Figure 3. The substantia nigra and ventral tegmental area (VTA) are located in the midbrain. The hindbrainhindbrain is located at the back of the head and looks like an extension of the spinal cord. It contains the medulla, pons, and cerebellum (Figure 4). The medullamedulla controls the automatic processes of the autonomic nervous system, such as breathing, blood pressure, and heart rate. The word ponspons literally means “bridge,” and as the name suggests, the pons serves to connect the brain and spinal cord. It also is involved in regulating brain activity during sleep. The medulla, pons, and midbrain together are known as the brainstem. Figure 4. The pons, medulla, and cerebellum make up the hindbrain. LINK TO LEARNINGLINK TO LEARNING Click on the link below to review each part of the brain and its purpose through the PsychSim Tutorial. The tutorial is only intended for practice. Please disregard the final screen that requests you submit answers to your instructor. • Brain and Behavior For a fun recap of the parts of the brain, watch the following short clip from the old cartoon, Pinky and the Brain: The cerebellumcerebellum (Latin for “little brain”) receives messages from muscles, tendons, joints, and structures in our ear to control balance, coordination, movement, and motor skills. The cerebellum is also thought to be an important area for processing some types of memories. In particular, procedural memory, or memory involved in learning and remembering how to perform tasks, is thought to be associated with the cerebellum. Recall that H. M. was unable to form new explicit memories, but he could learn new tasks. This is likely due to the fact that H. M.’s cerebellum remained intact. http://bcs.worthpublishers.com/webpub/Ektron/Myers_Psychology%2010e/PsychSim5_Tutorials/Brain_and_Behavior/brainandbehavior.htm A YouTube element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=1999 WHAT DO YOU THINK?: BRAIN DEAD AND ON LIFE SUPPORTWHAT DO YOU THINK?: BRAIN DEAD AND ON LIFE SUPPORT What would you do if your spouse or loved one was declared brain dead but his or her body was being kept alive by medical equipment? Whose decision should it be to remove a feeding tube? Should medical care costs be a factor? On February 25, 1990, a Florida woman named Terri Schiavo went into cardiac arrest, apparently triggered by a bulimic episode. She was eventually revived, but her brain had been deprived of oxygen for a long time. Brain scans indicated that there was no activity in her cerebral cortex, and she suffered from severe and permanent cerebral atrophy. Basically, Schiavo was in a vegetative state. Medical professionals determined that she would never again be able to move, talk, or respond in any way. To remain alive, she required a feeding tube, and there was no chance that her situation would ever improve. On occasion, Schiavo’s eyes would move, and sometimes she would groan. Despite the doctors’ insistence to the contrary, her parents believed that these were signs that she was trying to communicate with them. After 12 years, Schiavo’s husband argued that his wife would not have wanted to be kept alive with no feelings, sensations, or brain activity. Her parents, however, were very much against removing her feeding tube. Eventually, the case made its way to the courts, both in the state of Florida and at the federal level. By 2005, the courts found in favor of Schiavo’s husband, and the feeding tube was removed on March 18, 2005. Schiavo died 13 days later. Why did Schiavo’s eyes sometimes move, and why did she groan? Although the parts of her brain that control thought, voluntary movement, and feeling were completely damaged, her brainstem was still intact. Her medulla and pons maintained her breathing and caused involuntary movements of her eyes and the occasional groans. Over the 15-year period that she was on a feeding tube, Schiavo’s medical costs may have topped $7 million (Arnst, 2003). These questions were brought to popular conscience 25 years ago in the case of Terri Schiavo, and they persist today. In 2013, a 13-year-old girl who suffered complications after tonsil surgery was declared brain dead. There was a battle between her family, who wanted her to remain on life support, and the hospital’s policies regarding persons declared brain dead. In another complicated 2013–14 case in Texas, a pregnant EMT professional declared brain dead was kept alive for weeks, despite her spouse’s directives, which were based on her wishes should this situation arise. In this case, state laws designed to protect an unborn fetus came into consideration until doctors determined the fetus unviable. Decisions surrounding the medical response to patients declared brain dead are complex. What do you think about these issues? An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=1999 TRY ITTRY IT THINK IT OVERTHINK IT OVER You read about H. M.’s memory deficits following the bilateral removal of his hippocampus and amygdala. Have you encountered a character in a book, television program, or movie that suffered memory deficits? How was that character similar to and different from H. M.? GLOSSARYGLOSSARY amygdala:amygdala: structure in the limbic system involved in our experience of emotion and tying emotional meaning to our memories cerebellum:cerebellum: hindbrain structure that controls our balance, coordination, movement, and motor skills, and it is thought to be important in processing some types of memory cerebral cortex:cerebral cortex: surface of the brain that is associated with our highest mental capabilities forebrain:forebrain: largest part of the brain, containing the cerebral cortex, the thalamus, and the limbic system, among other structures hindbrain:hindbrain: division of the brain containing the medulla, pons, and cerebellum hippocampus:hippocampus: structure in the temporal lobe associated with learning and memory hypothalamus:hypothalamus: forebrain structure that regulates sexual motivation and behavior and a number of homeostatic processes; serves as an interface between the nervous system and the endocrine system limbic system:limbic system: collection of structures involved in processing emotion and memory medulla:medulla: hindbrain structure that controls automated processes like breathing, blood pressure, and heart rate midbrain:midbrain: division of the brain located between the forebrain and the hindbrain; contains the reticular formation pons:pons: hindbrain structure that connects the brain and spinal cord; involved in regulating brain activity during sleep reticular formation:reticular formation: midbrain structure important in regulating the sleep/wake cycle, arousal, alertness, and motor activity thalamus:thalamus: sensory relay for the brain ventral tegmental area (VTA):ventral tegmental area (VTA): midbrain structure where dopamine is produced: associated with mood, reward, and addiction Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Modification and adaptation, addition of tutorial. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution CC licensed content, Shared previouslyCC licensed content, Shared previously • The Brain and Spinal Cord. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.49:_Io4zP0c@7/The-Brain-and-Spinal-Cord#CNX_Psych_03_04_Lobes. LicenseLicense: CC BY: Attribution. LicenseLicense TermsTerms: Download for free at http://cnx.org/contents/4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@5.48 All rights reserved contentAll rights reserved content • pinky and the brain-brainstem. Authored byAuthored by: ctdalilah. Located atLocated at: https://www.youtube.com/watch?v=snO68aJTOpM. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License BRAIN IMAGING LEARNING OBJECTIVESLEARNING OBJECTIVES • Describe the types of techniques available to clinicians and researchers to image or scan the brain You have learned how brain injury can provide information about the functions of different parts of the brain. Increasingly, however, we are able to obtain that information using brain imagingbrain imaging techniques on individuals who have not suffered brain injury. In this section, we take a more in-depth look at some of the techniques that are available for imaging the brain, including techniques that rely on radiation, magnetic fields, or electrical activity within the brain. https://creativecommons.org/licenses/by/4.0/ http://cnx.org/contents/Sr8Ev5Og@5.49:_Io4zP0c@7/The-Brain-and-Spinal-Cord#CNX_Psych_03_04_Lobes https://creativecommons.org/licenses/by/4.0/ https://www.youtube.com/watch?v=snO68aJTOpM Figure 1. A CT scan can be used to show brain tumors. (a) The image on the left shows a healthy brain, whereas (b) the image on the right indicates a brain tumor in the left frontal lobe. (credit a: modification of work by “Aceofhearts1968″/Wikimedia Commons; credit b: modification of work by Roland Schmitt et al) Figure 2. A PET scan is helpful for showing activity in different parts of the brain. (credit: Health and Human Services Department, National Institutes of Health) Techniques Involving Radiation A computerized tomography (CT) scancomputerized tomography (CT) scan involves taking a number of x-rays of a particular section of a person’s body or brain (Figure 1). The x-rays pass through tissues of different densities at different rates, allowing a computer to construct an overall image of the area of the body being scanned. A CT scan is often used to determine whether someone has a tumor, or significant brain atrophy. Positron emission tomography (PET)Positron emission tomography (PET) scans create pictures of the living, active brain (Figure 2). An individual receiving a PET scan drinks or is injected with a mildly radioactive substance, called a tracer. Once in the bloodstream, the amount of tracer in any given region of the brain can be monitored. As brain areas become more active, more blood flows to that area. A computer monitors the movement of the tracer and creates a rough map of active and inactive areas of the brain during a given behavior. PET scans show little detail, are unable to pinpoint events precisely in time, and require that the brain be exposed to radiation; therefore, this technique has been replaced by the fMRI as an alternative diagnostic tool. However, combined with CT, PET technology is still being used in certain contexts. For example, CT/PET scans allow better imaging of the activity of neurotransmitter receptors and open new avenues in schizophrenia research. In this hybrid CT/PET technology, CT contributes clear images of brain structures, while PET shows the brain’s activity. Figure 3. An fMRI shows activity in the brain over time. This image represents a single frame from an fMRI. (credit: modification of work by Kim J, Matthews NL, Park S.) LINK TO LEARNINGLINK TO LEARNING Visit this virtual lab to learn more about MRI and fMRI. Techniques Involving Magnetic Fields In magnetic resonance imaging (MRI)magnetic resonance imaging (MRI), a person is placed inside a machine that generates a strong magnetic field. The magnetic field causes the hydrogen atoms in the body’s cells to move. When the magnetic field is turned off, the hydrogen atoms emit electromagnetic signals as they return to their original positions. Tissues of different densities give off different signals, which a computer interprets and displays on a monitor. Functional magnetic resonance imaging (fMRI)Functional magnetic resonance imaging (fMRI) operates on the same principles, but it shows changes in brain activity over time by tracking blood flow and oxygen levels. The fMRI provides more detailed images of the brain’s structure, as well as better accuracy in time, than is possible in PET scans (Figure 3). With their high level of detail, MRI and fMRI are often used to compare the brains of healthy individuals to the brains of individuals diagnosed with psychological disorders. This comparison helps determine what structural and functional differences exist between these populations. Techniques Involving Electrical Activity In some situations, it is helpful to gain an understanding of the overall activity of a person’s brain, without needing information on the actual location of the activity. Electroencephalography (EEG)Electroencephalography (EEG) serves this purpose by providing a measure of a brain’s electrical activity. An array of electrodes is placed around a person’s head (Figure 4). The signals received by the electrodes result in a printout of the electrical activity of his or her brain, or brainwaves, showing both the frequency (number of waves per second) and amplitude (height) of the recorded brainwaves, with an accuracy within milliseconds. Such information is especially helpful to researchers studying sleep patterns among individuals with sleep disorders. https://web.csulb.edu/~cwallis/482/fmri/fmri.html An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=1993 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=1993 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=1993 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=1993 TRY ITTRY IT Figure 4. Using caps with electrodes, modern EEG research can study the precise timing of overall brain activities. (credit: SMI Eye Tracking) An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=1993 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=1993 GLOSSARYGLOSSARY computerized tomography (CT) scan:computerized tomography (CT) scan: imaging technique in which a computer coordinates and integrates multiple x-rays of a given area electroencephalography (EEG):electroencephalography (EEG): recording the electrical activity of the brain via electrodes on the scalp functional magnetic resonance imaging (fMRI):functional magnetic resonance imaging (fMRI): MRI that shows changes in metabolic activity over time magnetic resonance imaging (MRI):magnetic resonance imaging (MRI): magnetic fields used to produce a picture of the tissue being imaged positron emission tomography (PET) scan:positron emission tomography (PET) scan: involves injecting individuals with a mildly radioactive substance and monitoring changes in blood flow to different regions of the brain An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=1993 Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Modification, adaptation, and original content. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution CC licensed content, Shared previouslyCC licensed content, Shared previously • Parts of the Nervous System. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.49:-xs7Ve8V@6/Parts-of-the-Nervous-System#CNX_Psych_03_03_Autonomic. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/contents/4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@5.48 LATERALIZATION AND NEUROPLASTICITY You may very well have heard that there are right-brained and left-brained people in the world. But, does this make sense to you? That you’re using only half of your brain? Better yet, does it make sense to you that we are using only 10% of our brain power, as is commonly purported? The reality is that we use ALL portions of our brains, and that there is no such thing as right- nor left-brained, yet these myths persist. Phineas Gage was the FIRST to really SHOW us not only about brain organization and lateralization, but also a little about brain plasticity. In OUR worlds, we can see this via the somewhat miraculous recovery of Gabby Giffords. Be sure to read the following and consider how many places you’ve heard the myth about using 10% of our brains: Do People Only Use 10% of Their Brains? https://creativecommons.org/licenses/by/4.0/ http://cnx.org/contents/Sr8Ev5Og@5.49:-xs7Ve8V@6/Parts-of-the-Nervous-System#CNX_Psych_03_03_Autonomic https://creativecommons.org/licenses/by/4.0/ https://www.today.com/health/if-gabby-giffords-still-struggles-speak-how-can-she-sing-2D11888324 https://www.today.com/health/if-gabby-giffords-still-struggles-speak-how-can-she-sing-2D11888324 https://www.scientificamerican.com/article/do-people-only-use-10-percent-of-their-brains/?redirect=1 NATURE AND NURTURE What you’ll learn to do: explain how nature, nurture, and epigenetics influence personality and behavior How do we become who we are? Traditionally, people’s answers have placed them in one of two camps: nature or nurture. The one says genes determine an individual while the other claims the environment is the linchpin for development. Since the 16th century, when the terms “nature” and “nurture” first came into use, many people have spent ample time debating which is more important, but these discussions have more often led to ideological cul-de-sacs rather than pinnacles of insight. New research into epigenetics—the science of how the environment influences genetic expression—is changing the conversation. As psychologist David S. Moore explains in his newest book, The Developing Genome, this burgeoning field reveals that what counts is not what genes you have so much as what your genes are doing. And what your genes are doing is influenced by the ever-changing environment they’re in. Factors like stress, nutrition, and exposure to toxins all play a role in how genes are expressed—essentially which genes are turned on or off. Unlike the static conception of nature or nurture, epigenetic research demonstrates how genes and environments continuously interact to produce characteristics throughout a lifetime. LEARNING OBJECTIVESLEARNING OBJECTIVES • Investigate the historic nature vs. nurture debate and describe techniques psychologists use to learn about the origin of traits https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/11/15044853/1024px-DNA_methylation Figure 1. Researchers have learned a great deal about the nature-nurture dynamic by working with animals. But of course many of the techniques used to study animals cannot be applied to people. Separating these two influences in human subjects is a greater research challenge. [Photo: mharrsch] • Explain the basic principles of the theory of evolution by natural selection, genetic variation, and mutation The Nature vs. Nurture Debate Are you the way you are because you were born that way, or because of the way you were raised? Do your genetics and biology dictate your personality and behavior, or is it your environment and how you were raised? These questions are central to the age-old nature-nurturenature-nurture debate. In the history of psychology, no other question has caused so much controversy and offense: We are so concerned with nature–nurture because our very sense of moral character seems to depend on it. While we may admire the athletic skills of a great basketball player, we think of his height as simply a gift, a payoff in the “genetic lottery.” For the same reason, no one blames a short person for his height or someone’s congenital disability on poor decisions: To state the obvious, it’s “not their fault.” But we do praise the concert violinist (and perhaps her parents and teachers as well) for her dedication, just as we condemn cheaters, slackers, and bullies for their bad behavior.The problem is, most human characteristics aren’t usually as clear-cut as height or instrument-mastery, affirming our nature–nurture expectations strongly one way or the other. In fact, even the great violinist might have some inborn qualities—perfect pitch, or long, nimble fingers—that support and reward her hard work. And the basketball player might have eaten a diet while growing up that promoted his genetic tendency for being tall. When we think about our own qualities, they seem under our control in some respects, yet beyond our control in others. And often the traits that don’t seem to have an obvious cause are the ones that concern us the most and are far more personally significant. What about how much we drink or worry? What about our honesty, or religiosity, or sexual orientation? They all come from that uncertain zone, neither fixed by nature nor totally under our own control. One major problem with answering nature-nurture questions about people is, how do you set up an experiment? In nonhuman animals, there are relatively straightforward experiments for tackling nature–nurture questions. Say, for example, you are interested in aggressiveness in dogs. You want to test for the more important determinant of aggression: being born to aggressive dogs or being raised by them. You could mate two aggressive dogs—angry Chihuahuas—together, and mate two nonaggressive dogs—happy beagles—together, then switch half the puppies from each litter between the different sets of parents to raise. You would then have puppies born to aggressive parents (the Chihuahuas) but being raised by nonaggressive parents (the Beagles), and vice versa, in litters that mirror each other in puppy distribution. The big questions are: Would the Chihuahua parents raise aggressive beagle puppies? Would the beagle parents raise nonaggressive Chihuahua puppies? Would the puppies’ nature win out, regardless of who raised them? Or… would the result be a combination of nature and nurture? Much of the most significant nature–nurture research has been done in this way (Scott & Fuller, 1998), and animal breeders have been doing it successfully for thousands of years. In fact, it is fairly easy to breed animals for behavioral traits. With people, however, we can’t assign babies to parents at random, or select parents with certain behavioral characteristics to mate, merely in the interest of science (though history does include horrific examples of such practices, in misguided attempts at “eugenics,” the shaping of human characteristics through intentional breeding). In typical human families, children’s biological parents raise them, so it is very difficult to know whether children act like their parents due to genetic (nature) or environmental (nurture) reasons. Nevertheless, despite our restrictions on setting up human-based experiments, we do see real-world examples of nature-nurture at work in the human sphere—though they only provide partial answers to our many questions. The science of how genes and environments work together to influence behavior is called behavioral geneticsbehavioral genetics. The easiest opportunity we https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/10/21142023/doggies https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/10/21142023/doggies Figure 2. Studies focused on twins have lead to important insights about the biological origins of many personality characteristics. [Photo: ethermoon] have to observe this is the adoption studyadoption study. When children are put up for adoption, the parents who give birth to them are no longer the parents who raise them. This setup isn’t quite the same as the experiments with dogs (children aren’t assigned to random adoptive parents in order to suit the particular interests of a scientist) but adoption still tells us some interesting things, or at least confirms some basic expectations. For instance, if the biological child of tall parents were adopted into a family of short people, do you suppose the child’s growth would be affected? What about the biological child of a Spanish-speaking family adopted at birth into an English- speaking family? What language would you expect the child to speak? And what might these outcomes tell you about the difference between height and language in terms of nature-nurture? Another option for observing nature-nurture in humans involves twin studiestwin studies. There are two types of twins: monozygotic (MZ) and dizygotic (DZ). Monozygotic twins, also called “identical” twins, result from a single zygote (fertilized egg) and have the same DNA. They are essentially clones. Dizygotic twins, also known as “fraternal” twins, develop from two zygotes and share 50% of their DNA. Fraternal twins are ordinary siblings who happen to have been born at the same time. To analyze nature–nurture using twins, we compare the similarity of MZ and DZ pairs. Sticking with the features of height and spoken language, let’s take a look at how nature and nurture apply: Identical twins, unsurprisingly, are almost perfectly similar for height. The heights of fraternal twins, however, are like any other sibling pairs: more similar to each other than to people from other families, but hardly identical. This contrast between twin types gives us a clue about the role genetics plays in determining height. Now consider spoken language. If one identical twin speaks Spanish at home, the co-twin with whom she is raised almost certainly does too. But the same would be true for a pair of fraternal twins raised together. In terms of spoken language, fraternal twins are just as similar as identical twins, so it appears that the genetic match of identical twins doesn’t make much difference. Twin and adoption studies are two instances of a much broader class of methods for observing nature-nurture called quantitative geneticsquantitative genetics, the scientific discipline in which similarities among individuals are analyzed based on how biologically related they are. We can do these studies with siblings and half-siblings, cousins, twins who have been separated at birth and raised separately (Bouchard, Lykken, McGue, & Segal, 1990; such twins are very rare and play a smaller role than is commonly believed in the science of nature–nurture), or with entire extended families (see Plomin, DeFries, Knopik, & Neiderhiser, 2012, for a complete introduction to research methods relevant to nature–nurture). For better or for worse, contentions about nature–nurture have intensified because quantitative genetics produces a number called a heritability coefficientheritability coefficient, varying from 0 to 1, that is meant to provide a single measure of genetics’ influence of a trait. In a general way, a heritability coefficient measures how strongly differences among individuals are related to differences among their genes. But beware: Heritability coefficients, although simple to compute, are deceptively difficult to interpret. Nevertheless, numbers that provide simple answers to complicated questions tend to have a strong influence on the human imagination, and a great deal of time has been spent discussing whether the heritability of intelligence or personality or depression is equal to one number or another. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/10/21142159/twoboys https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/10/21142159/twoboys Figure 3. Quantitative genetics uses statistical methods to study the effects that both heredity and environment have on test subjects. These methods have provided us with the heritability coefficient which measures how strongly differences among individuals for a trait are related to differences among their genes. [Image: EMSL] Figure 4. Research over the last half century has revealed how central genetics are to behavior. The more genetically related people are the more similar they are not just physically but also in terms of personality and behavior. [Photo: 藍川芥 aikawake] One reason nature–nurture continues to fascinate us so much is that we live in an era of great scientific discovery in genetics, comparable to the times of Copernicus, Galileo, and Newton, with regard to astronomy and physics. Every day, it seems, new discoveries are made, new possibilities proposed. When Francis Galton first started thinking about nature–nurture in the late-19th century he was very influenced by his cousin, Charles Darwin, but genetics per se was unknown. Mendel’s famous work with peas, conducted at about the same time, went undiscovered for 20 years; quantitative genetics was developed in the 1920s; DNA was discovered by Watson and Crick in the 1950s; the human genome was completely sequenced at the turn of the 21st century; and we are now on the verge of being able to obtain the specific DNA sequence of anyone at a relatively low cost. No one knows what this new genetic knowledge will mean for the study of nature–nurture, but as we will see in the next section, answers to nature–nurture questions have turned out to be far more difficult and mysterious than anyone imagined. What Have We Learned About Nature–Nurture? It would be satisfying to be able to say that nature–nurture studies have given us conclusive and complete evidence about where traits come from, with some traits clearly resulting from genetics and others almost entirely from environmental factors, such as childrearing practices and personal will; but that is not the case. Instead, everything has turned out to have some footing in genetics. The more genetically-related people are, the more similar they are—for everything: height, weight, intelligence, personality, mental illness, etc. Sure, it seems like common sense that some traits have a genetic bias. For example, adopted children resemble their biological parents even if they have never met them, and identical twins are more similar to each other than are fraternal twins. And while certain psychological traits, such as personality or mental illness (e.g., schizophrenia), seem reasonably influenced by genetics, it turns out that the same is true for political attitudes, how much television people watch (Plomin, Corley, DeFries, & Fulker, 1990), and whether or not they get divorced (McGue & Lykken, 1992). It may seem surprising, but genetic influence on behavior is a relatively recent discovery. In the middle of the 20th century, psychology was dominated by the doctrine of behaviorism, which held that behavior could only be explained in terms of environmental factors. Psychiatry concentrated on psychoanalysis, which probed for roots of behavior in individuals’ early life-histories. The truth is, neither behaviorism nor psychoanalysis is incompatible with genetic influences on behavior, and neither Freud nor Skinner was naive about the importance of organic processes in behavior. Nevertheless, in their day it was widely thought that children’s personalities were shaped entirely by imitating their parents’ behavior, and that schizophrenia was caused by certain kinds of “pathological mothering.” Whatever the outcome of our broader discussion of nature–nurture, the basic fact that the best predictors of an adopted child’s personality or mental health are found in the biological parents he or she has never met, rather than in the adoptive parents who raised him or her, presents a significant challenge to purely environmental explanations of personality or psychopathology. The message is clear: You can’t leave genes out of the equation. But keep in https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/10/21142506/dna3 https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/10/21142506/dna3 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2040 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2040 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2040 TRY ITTRY IT mind, no behavioral traits are completely inherited, so you can’t leave the environment out altogether, either. Trying to untangle the various ways nature-nurture influences human behavior can be messy, and often common- sense notions can get in the way of good science. One very significant contribution of behavioral genetics that has changed psychology for good can be very helpful to keep in mind: When your subjects are biologically- related, no matter how clearly a situation may seem to point to environmental influence, it is never safe to interpret a behavior as wholly the result of nurture without further evidence. For example, when presented with data showing that children whose mothers read to them often are likely to have better reading scores in third grade, it is tempting to conclude that reading to your kids out loud is important to success in school; this may well be true, but the study as described is inconclusive, because there are genetic as well as environmental pathways between the parenting practices of mothers and the abilities of their children. This is a case where “correlation does not imply causation,” as they say. To establish that reading aloud causes success, a scientist can either study the problem in adoptive families (in which the genetic pathway is absent) or by finding a way to randomly assign children to oral reading conditions. THINK IT OVERTHINK IT OVER • Is your personality more like one of your parents than the other? If you have a sibling, is his or her personality like yours? In your family, how did these similarities and differences develop? What do you think caused them? • Can you think of a human characteristic for which genetic differences would play almost no role? Defend your choice. • Do you think the time will come when we will be able to predict almost everything about someone by examining their DNA on the day they are born? • Identical twins are more similar than fraternal twins for the trait of aggressiveness, as well as for criminal behavior. Do these facts have implications for the courtroom? If it can be shown that a violent criminal had violent parents, should it make a difference in culpability or sentencing? Psychological researchers study genetics in order to better understand the biological basis that contributes to certain behaviors. While all humans share certain biological mechanisms, we are each unique. And while our bodies have many of the same parts—brains and hormones and cells with genetic codes—these are expressed in a wide variety of behaviors, thoughts, and reactions. Why do two people infected by the same disease have different outcomes: one surviving and one succumbing to the ailment? How are genetic diseases passed through family lines? Are there genetic components to psychological disorders, such as depression or schizophrenia? To what extent might there be a psychological basis to health conditions such as childhood obesity? Figure 5. Normal blood cells travel freely through the blood vessels, while sickle-shaped cells form blockages preventing blood flow. LINK TO LEARNINGLINK TO LEARNING Visit this website to learn more about how a mutation in DNA leads to sickle-cell anemia. To explore these questions, let’s start by focusing on a specific disease, sickle-cell anemia, and how it might affect two infected sisters. Sickle-cell anemiaSickle-cell anemia is a genetic condition in which red blood cells, which are normally round, take on a crescent-like shape (Figure 5). The changed shape of these cells affects how they function: sickle-shaped cells can clog blood vessels and block blood flow, leading to high fever, severe pain, swelling, and tissue damage. Many people with sickle-cell anemia—and the particular genetic mutation that causes it—die at an early age. While the notion of “survival of the fittest” may suggest that people suffering from this disease have a low survival rate and therefore the disease will become less common, this is not the case. Despite the negative evolutionary effects associated with this genetic mutation, the sickle-cell gene remains relatively common among people of African descent. Why is this? The explanation is illustrated with the following scenario. Imagine two young women—Luwi and Sena—sisters in rural Zambia, Africa. Luwi carries the gene for sickle-cell anemia; Sena does not carry the gene. Sickle-cell carriers have one copy of the sickle-cell gene but do not have full- blown sickle-cell anemia. They experience symptoms only if they are severely dehydrated or are deprived of oxygen (as in mountain climbing). Carriers are thought to be immune from malaria (an often deadly disease that is widespread in tropical climates) because changes in their blood chemistry and immune functioning prevent the malaria parasite from having its effects (Gong, Parikh, Rosenthal, & Greenhouse, 2013). However, full-blown sickle-cell anemia, with two copies of the sickle-cell gene, does not provide immunity to malaria. While walking home from school, both sisters are bitten by mosquitos carrying the malaria parasite. Luwi does not get malaria because she carries the sickle-cell mutation. Sena, on the other hand, develops malaria and dies just two weeks later. Luwi survives and eventually has children, to whom she may pass on the sickle-cell mutation. Malaria is rare in the United States, so the sickle-cell gene benefits nobody: the gene manifests primarily in health problems—minor in carriers, severe in the full-blown disease—with no health benefits for carriers. However, the situation is quite different in other parts of the world. In parts of Africa where malaria is prevalent, having the sickle-cell mutation does provide health benefits for carriers (protection from malaria). This is precisely the situation that Charles Darwin describes in the theory of evolution by natural selectiontheory of evolution by natural selection (Figure 6). In simple terms, the theory states that organisms that are better suited for their environment will survive and reproduce, while those that are poorly suited for their environment will die off. In our example, we can see that as a carrier, Luwi’s mutation is highly adaptive in her African homeland; however, if she resided in the United States (where malaria is much less common), her mutation could prove costly—with a high probability of the disease in her descendants and minor health problems of her own. https://www.dnalc.org/resources/3d/17-sickle-cell.html Figure 6. (a) In 1859, Charles Darwin proposed his theory of evolution by natural selection in his book, On the Origin of Species. (b) The book contains just one illustration: this diagram that shows how species evolve over time through natural selection. DIG DEEPER: TWO PERSPECTIVES ON GENETICS AND BEHAVIORDIG DEEPER: TWO PERSPECTIVES ON GENETICS AND BEHAVIOR It’s easy to get confused about two fields that study the interaction of genes and the environment, such as the fields of evolutionary psychologyevolutionary psychology and behavioral geneticsbehavioral genetics. How can we tell them apart? In both fields, it is understood that genes not only code for particular traits, but also contribute to certain patterns of cognition and behavior. Evolutionary psychology focuses on how universal patterns of behavior and cognitive processes have evolved over time. Therefore, variations in cognition and behavior would make individuals more or less successful in reproducing and passing those genes to their offspring. Evolutionary psychologists study a variety of psychological phenomena that may have evolved as adaptations, including fear response, food preferences, mate selection, and cooperative behaviors (Confer et al., 2010). Whereas evolutionary psychologists focus on universal patterns that evolved over millions of years, behavioral geneticists study how individual differences arise, in the present, through the interaction of genes and the environment. When studying human behavior, behavioral geneticists often employ twin and adoption studies to research questions of interest. Twin studies compare the rates that a given behavioral trait is shared among identical and fraternal twins; adoption studies compare those rates among biologically related relatives and adopted relatives. Both approaches provide some insight into the relative importance of genes and environment for the expression of a given trait. LINK TO LEARNINGLINK TO LEARNING Watch this interview with renowned evolutionary psychologist Davis Buss for an explanation of how a psychologist approaches evolution and how this approach fits within the field of social science. https://youtu.be/xbRCFuet0Nk An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2040 TRY ITTRY IT Genetic Variation Genetic variation, the genetic difference between individuals, is what contributes to a species’ adaptation to its environment. In humans, genetic variation begins with an egg, about 100 million sperm, and fertilization. Fertile women ovulate roughly once per month, releasing an egg from follicles in the ovary. The egg travels, via the fallopian tube, from the ovary to the uterus, where it may be fertilized by a sperm. The egg and the sperm each contain 23 chromosomes. ChromosomesChromosomes are long strings of genetic material known as deoxyribonucleic acid (DNA)deoxyribonucleic acid (DNA). DNA is a helix-shaped molecule made up of nucleotide base pairs. In each chromosome, sequences of DNA make up genesgenes that control or partially control a number of visible characteristics, known as traits, such as eye color, hair color, and so on. A single gene may have multiple possible variations, or alleles. An alleleallele is a specific version of a gene. So, a given gene may code for the trait of hair color, and the different alleles of that gene affect which hair color an individual has. When a sperm and egg fuse, their 23 chromosomes pair up and create a zygote with 23 pairs of chromosomes. Therefore, each parent contributes half the genetic information carried by the offspring; the resulting physical characteristics of the offspring (called the phenotype) are determined by the interaction of genetic material supplied by the parents (called the genotype). A person’s genotypegenotype is the genetic makeup of that individual. Phenotype,Phenotype, on the other hand, refers to the individual’s inherited physical characteristics (Figure 7). Figure 7. (a) Genotype refers to the genetic makeup of an individual based on the genetic material (DNA) inherited from one’s parents. (b) Phenotype describes an individual’s observable characteristics, such as hair color, skin color, height, and build. (credit a: modification of work by Caroline Davis; credit b: modification of work by Cory Zanker) Most traits are controlled by multiple genes, but some traits are controlled by one gene. A characteristic like cleftcleft chinchin, for example, is influenced by a single gene from each parent. In this example, we will call the gene for cleft chin “B,” and the gene for smooth chin “b.” Cleft chin is a dominant trait, which means that having the dominantdominant alleleallele either from one parent (Bb) or both parents (BB) will always result in the phenotype associated with the dominant allele. When someone has two copies of the same allele, they are said to be homozygoushomozygous for that allele. When someone has a combination of alleles for a given gene, they are said to be heterozygousheterozygous. For example, smooth chin is a recessive trait, which means that an individual will only display the smooth chin phenotype if they are homozygous for that recessive allelerecessive allele (bb). Imagine that a woman with a cleft chin has a child with a man with a smooth chin. What type of chin will their child have? The answer to that depends on which alleles each parent carries. If the woman is homozygous for cleft chin (BB), her offspring will always have cleft chin. It gets a little more complicated, however, if the mother is heterozygous for this gene (Bb). Since the father has a smooth chin—therefore homozygous for the recessive allele (bb)—we can expect the offspring to have a 50% chance of having a cleft chin and a 50% chance of having a smooth chin (Figure 8). Figure 8. (a) A Punnett square is a tool used to predict how genes will interact in the production of offspring. The capital B represents the dominant allele, and the lowercase b represents the recessive allele. In the example of the cleft chin, where B is cleft chin (dominant allele), wherever a pair contains the dominant allele, B, you can expect a cleft chin phenotype. You can expect a smooth chin phenotype only when there are two copies of the recessive allele, bb. (b) A cleft chin, shown here, is an inherited trait. Sickle-cell anemia is just one of many genetic disorders caused by the pairing of two recessive genes. For example, phenylketonuria (PKU)phenylketonuria (PKU) is a condition in which individuals lack an enzyme that normally converts harmful amino acids into harmless byproducts. If someone with this condition goes untreated, he or she will experience significant deficits in cognitive function, seizures, and increased risk of various psychiatric disorders. Because PKU is a recessive trait, each parent must have at least one copy of the recessive allele in order to produce a child with the condition (Figure 9). Figure 9. In this Punnett square, N represents the normal allele, and p represents the recessive allele that is associated with PKU. If two individuals mate who are both heterozygous for the allele associated with PKU, their offspring have a 25% chance of expressing the PKU phenotype. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2040 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2040 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2040 TRY ITTRY IT GLOSSARYGLOSSARY adoption studyadoption study: a behavior genetic research method that involves comparison of adopted children to their adoptive and biological parents allele:allele: specific version of a gene behavioral geneticsbehavioral genetics: the empirical science of how genes and environments combine to generate behavior chromosome:chromosome: long strand of genetic information So far, we have discussed traits that involve just one gene, but few human characteristics are controlled by a single gene. Most traits are polygenicpolygenic: controlled by more than one gene. Height is one example of a polygenic trait, as are skin color and weight. Where do harmful genes that contribute to diseases like PKU come from? Gene mutations provide one source of harmful genes. A mutationmutation is a sudden, permanent change in a gene. While many mutations can be harmful or lethal, once in a while, a mutation benefits an individual by giving that person an advantage over those who do not have the mutation. Recall that the theory of evolution asserts that individuals best adapted to their particular environments are more likely to reproduce and pass on their genes to future generations. In order for this process to occur, there must be competition—more technically, there must be variability in genes (and resultant traits) that allow for variation in adaptability to the environment. If a population consisted of identical individuals, then any dramatic changes in the environment would affect everyone in the same way, and there would be no variation in selection. In contrast, diversity in genes and associated traits allows some individuals to perform slightly better than others when faced with environmental change. This creates a distinct advantage for individuals best suited for their environments in terms of successful reproduction and genetic transmission. deoxyribonucleic acid (DNA):deoxyribonucleic acid (DNA): helix-shaped molecule made of nucleotide base pairs dominant allele:dominant allele: allele whose phenotype will be expressed in an individual that possesses that allele genetic environmental correlation:genetic environmental correlation: view of gene-environment interaction that asserts our genes affect our environment, and our environment influences the expression of our genes genotype:genotype: genetic makeup of an individual heterozygous:heterozygous: consisting of two different alleles heritability coefficientheritability coefficient: an easily misinterpreted statistical construct that purports to measure the role of genetics in the explanation of differences among individuals homozygous:homozygous: consisting of two identical alleles mutation:mutation: sudden, permanent change in a gene phenotype:phenotype: individual’s inheritable physical characteristics polygenic:polygenic: multiple genes affecting a given trait quantitative geneticsquantitative genetics: scientific and mathematical methods for inferring genetic and environmental processes based on the degree of genetic and environmental similarity among organisms recessive allele:recessive allele: allele whose phenotype will be expressed only if an individual is homozygous for that allele theory of evolution by natural selection:theory of evolution by natural selection: states that organisms that are better suited for their environments will survive and reproduce compared to those that are poorly suited for their environments twin studiestwin studies: a behavior genetic research method that involves comparison of the similarity of identical (monozygotic; MZ) and fraternal (dizygotic; DZ) twins Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Modification, adaptation, and original content. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike CC licensed content, Shared previouslyCC licensed content, Shared previously • DNA image. Provided byProvided by: Wikimedia. Located atLocated at: https://simple.wikipedia.org/wiki/DNA_methylation#/media/File:DNA_methylation . LicenseLicense: CC BY-SA: Attribution-ShareAlike • The End of Nature Versus Nurture. Authored byAuthored by: Evan Nesterak. Located atLocated at: http://thepsychreport.com/books/the-end-of-nature-versus-nurture/. ProjectProject: The Psych Report. LicenseLicense: CC BY-NC-SA: Attribution- NonCommercial-ShareAlike • The Nature-Nurture Question. Authored byAuthored by: Eric Turkheimer. Provided byProvided by: University of Virginia. Located atLocated at: http://nobaproject.com/modules/the-nature-nurture-question. ProjectProject: The Noba Project. LicenseLicense: CC BY-NC- SA: Attribution-NonCommercial-ShareAlike • Psychology. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@4.100:1/Psychology. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/content/col11629/latest/. GENE-ENVIRONMENT INTERACTIONS LEARNING OBJECTIVESLEARNING OBJECTIVES • Describe epigenetics and examine how gene-environment interactions are critical for expression of physical and psychological characteristics Genes do not exist in a vacuum. Although we are all biological organisms, we also exist in an environment that is incredibly important in determining not only when and how our genes express themselves, but also in what combination. Each of us represents a unique interaction between our genetic makeup and our environment; range of reaction is one way to describe this interaction. Range of reactionRange of reaction asserts that our genes set the boundaries within which we can operate, and our environment interacts with the genes to determine where in that range we will fall. For example, if an individual’s genetic makeup predisposes her to high levels of intellectual potential and she is reared in a rich, stimulating environment, then she will be more likely to achieve her full potential than if she were raised under conditions of significant deprivation. According to the concept of range of reaction, genes set definite limits on potential, and environment determines how much of that potential is achieved. https://creativecommons.org/licenses/by-nc-sa/4.0/ https://simple.wikipedia.org/wiki/DNA_methylation#/media/File:DNA_methylation https://creativecommons.org/licenses/by-sa/4.0/ http://thepsychreport.com/books/the-end-of-nature-versus-nurture/ https://creativecommons.org/licenses/by-nc-sa/4.0/ https://creativecommons.org/licenses/by-nc-sa/4.0/ http://nobaproject.com/modules/the-nature-nurture-question https://creativecommons.org/licenses/by-nc-sa/4.0/ https://creativecommons.org/licenses/by-nc-sa/4.0/ http://cnx.org/contents/4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@4.100:1/Psychology https://creativecommons.org/licenses/by/4.0/ Figure 1. Nature and nurture work together like complex pieces of a human puzzle. The interaction of our environment and genes makes us the individuals we are. (credit “puzzle”: modification of work by Cory Zanker; credit “houses”: modification of work by Ben Salter; credit “DNA”: modification of work by NHGRI) An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=1975 LINK TO LEARNINGLINK TO LEARNING Visit this site for an engaging video primer on the epigenetics of twin studies. Another perspective on the interaction between genes and the environment is the concept of geneticgenetic environmental correlationenvironmental correlation. Stated simply, our genes influence our environment, and our environment influences the expression of our genes (Figure 1). Not only do our genes and environment interact, as in range of reaction, but they also influence one another bidirectionally. For example, the child of an NBA player would probably be exposed to basketball from an early age. Such exposure might allow the child to realize his or her full genetic, athletic potential. Thus, the parents’ genes, which the child shares, influence the child’s environment, and that environment, in turn, is well suited to support the child’s genetic potential. In another approach to gene-environment interactions, the field of epigeneticsepigenetics looks beyond the genotype itself and studies how the same genotype can be expressed in different ways. In other words, researchers study how the same genotype can lead to very different phenotypes. As mentioned earlier, gene expression is often influenced by environmental context in ways that are not entirely obvious. For instance, identical twins share the same genetic information (identical twinsidentical twins develop from a single fertilized egg that split, so the genetic material is exactly the same in each; in contrast, fraternal twinsfraternal twins develop from two different eggs fertilized by different sperm, so the genetic material varies as with non-twin siblings). But even with identical genes, there remains an incredible amount of variability in how gene expression can unfold over the course of each twin’s life. Sometimes, one twin will develop a disease and the other will not. In one example, Tiffany, an identical twin, died from cancer at age 7, but her twin, now 19 years old, has never had cancer. Although these individuals share an identical genotype, their phenotypes differ as a result of how that genetic information is expressed over time. The epigenetic perspective is very different from range of reaction, because here the genotype is not fixed and limited. http://learn.genetics.utah.edu/content/epigenetics/twins/ Figure 2. Identical twins are the perfect example of epigenetics. Although they share exactly the same DNA, their unique experiences in life will cause some genes (and not others) to express themselves. This is why, over time, identical twins come to look and behave differently. [Image: Inese Dunajeva] GenesGenes affect more than our physical characteristics. Indeed, scientists have found genetic linkages to a number of behavioral characteristics, ranging from basic personality traits to sexual orientation to spirituality (for examples, see Mustanski et al., 2005; Comings, Gonzales, Saucier, Johnson, & MacMurray, 2000). Genes are also associated with temperament and a number of psychological disorders, such as depression and schizophrenia. So while it is true that genes provide the biological blueprints for our cells, tissues, organs, and body, they also have significant impact on our experiences and our behaviors. Let’s look at the following findings regarding schizophrenia in light of our three views of gene-environment interactions. Which view do you think best explains this evidence? In a study of people who were given up for adoption, adoptees whose biological mothers had schizophrenia and who had been raised in a disturbed family environment were much more likely to develop schizophrenia or another psychotic disorder than were any of the other groups in the study: • Of adoptees whose biological mothers had schizophrenia (high genetic risk) and who were raised in disturbed family environments, 36.8% were likely to develop schizophrenia. • Of adoptees whose biological mothers had schizophrenia (high genetic risk) and who were raised in healthy family environments, 5.8% were likely to develop schizophrenia. • Of adoptees with a low genetic risk (whose mothers did not have schizophrenia) and who were raised in disturbed family environments, 5.3% were likely to develop schizophrenia. • Of adoptees with a low genetic risk (whose mothers did not have schizophrenia) and who were raised in healthy family environments, 4.8% were likely to develop schizophrenia (Tienari et al., 2004). The study shows that adoptees with high genetic risk were especially likely to develop schizophrenia only if they were raised in disturbed home environments. This research lends credibility to the notion that both genetic vulnerability and environmental stress are necessary for schizophrenia to develop, and that genes alone do not tell the full tale. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/10/21125943/twinsies https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/10/21125943/twinsies DIG DEEPER: PARENTAL INVESTMENT AND PROGRAMMING OF STRESSDIG DEEPER: PARENTAL INVESTMENT AND PROGRAMMING OF STRESS RESPONSES IN OFFSPRINGRESPONSES IN OFFSPRING The most comprehensive study to date of variations in parental investment and epigenetic inheritance in mammals is that of the maternally transmitted responses to stress in rats. In rat pups, maternal nurturing (licking and grooming) during the first week of life is associated with long-term programming of individual differences in stress responsiveness, emotionality, cognitive performance, and reproductive behavior (Caldji et al., 1998; Francis, Diorio, Liu, & Meaney, 1999; Liu et al., 1997; Myers, Brunelli, Shair, Squire, & Hofer, 1989; Stern, 1997). In adulthood, the offspring of mothers that exhibit increased levels of pup licking and grooming over the first week of life show increased expression of the glucocorticoid receptor in the hippocampus (a brain structure associated with stress responsivity as well as learning and memory) and a lower hormonal response to stress compared with adult animals reared by low licking and grooming mothers (Francis et al., 1999; Liu et al., 1997). Moreover, rat pups that received low levels of maternal licking and grooming during the first week of life showed decreased histone acetylation and increased DNA methylation of a neuron-specific promoter of the glucocorticoid receptor gene (Weaver et al., 2004). The expression of this gene is then reduced, the number of glucocorticoid receptors in the brain is decreased, and the animals show a higher hormonal response to stress throughout their life. The effects of maternal care on stress hormone responses and behavior in the offspring can be eliminated in adulthood by pharmacological treatment (HDAC inhibitor trichostatin A, TSA) or dietary amino acid supplementation (methyl donor L-methionine), treatments that influence histone acetylation, DNA methylation, and expression of the glucocorticoid receptor gene (Weaver et al., 2004;Weaver et al., 2005). This series of experiments shows that histone acetylation and DNA methylation of the glucocorticoid receptor gene promoter is a necessary link in the process leading to the long-term physiological and behavioral sequelae of poor maternal care. This points to a possible molecular target for treatments that may reverse or ameliorate the traces of childhood maltreatment. Several studies have attempted to determine to what extent the findings from model animals are transferable to humans. Examination of post-mortem brain tissue from healthy human subjects found that the human equivalent of the glucocorticoid receptor gene promoter (NR3C1 exon 1F promoter) is also unique to the individual (Turner, Pelascini, Macedo, & Muller, 2008). A similar study examining newborns showed that methylation of the glucocorticoid receptor gene promoter maybe an early epigenetic marker of maternal mood and risk of increased hormonal responses to stress in infants 3 months of age (Oberlander et al., 2008). Although further studies are required to examine the functional consequence of this DNA methylation, these findings are consistent with our studies in the neonate and adult offspring of low licking and grooming mothers that show increased DNA methylation of the promoter of the glucocorticoid receptor gene, decreased glucocorticoid receptor gene expression, and increased hormonal responses to stress (Weaver et al., 2004). Examination of brain tissue from suicide victims found that the human glucocorticoid receptor gene promoter is also more methylated in the brains of individuals who had experienced maltreatment during childhood (McGowan et al., 2009). Examination of blood samples from adult patients with bipolar disorder, who also retrospectively reported on their experiences of childhood abuse and neglect, found that the degree of DNA methylation of the human glucocorticoid receptor gene promoter was strongly positively related to the reported experience of childhood maltreatment decades earlier. Watch this video to see another example of how diet can alter the phenotype of genetically identical mice. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=1975 TRY ITTRY IT https://www.youtube.com/watch?v=YfAV4poRkJ4 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=1975 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=1975 GLOSSARYGLOSSARY epigenome:epigenome: a dynamic layer of information associated with DNA that differs between individuals and can be altered through various experiences and environments epigenetics:epigenetics: study of gene-environment interactions, such as how the same genotype leads to different phenotypes fraternal twins:fraternal twins: twins who develop from two different eggs fertilized by different sperm, so their genetic material varies the same as in non-twin siblings gene:gene: sequence of DNA that controls or partially controls physical characteristics identical twins:identical twins: twins that develop from the same sperm and egg range of reaction:range of reaction: asserts our genes set the boundaries within which we can operate, and our environment interacts with the genes to determine where in that range we will fall An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=1975 Licensing & AttributionsLicensing & Attributions CC licensed content, Shared previouslyCC licensed content, Shared previously • Human Genetics. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.49:vQpw884b@8/Human-Genetics. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/ contents/4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@5.48 • Epigenetics in Psychology (Dig Deeper activity and image of twins). Authored byAuthored by: Ian Weaver. Provided byProvided by: Dalhousie University. Located atLocated at: http://nobaproject.com/modules/epigenetics-in-psychology?r=LDExNDY3. ProjectProject: The Noba Project. LicenseLicense: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike All rights reserved contentAll rights reserved content • Introducing epigenetics - Intro to Psychology. Authored byAuthored by: Udacity. Located atLocated at: https://www.youtube.com/watch?v=JCZ-flJ-QxA. LicenseLicense: Other. License TermsLicense Terms: Download for free at http://cnx.org/contents/ 4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@5.48 PUTTING IT TOGETHER: BIOPSYCHOLOGY LEARNING OBJECTIVESLEARNING OBJECTIVES In this module, you learned to • identify the basic structures of a neuron, the function of each structure, and how messages travel through the neuron • describe the role of the nervous system and endocrine systems • identify and describe the parts of the brain http://cnx.org/contents/Sr8Ev5Og@5.49:vQpw884b@8/Human-Genetics https://creativecommons.org/licenses/by/4.0/ http://nobaproject.com/modules/epigenetics-in-psychology?r=LDExNDY3 https://creativecommons.org/licenses/by-nc-sa/4.0/ https://www.youtube.com/watch?v=JCZ-flJ-QxA An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2852 • explain how nature, nurture, and epigenetics influence personality and behavior Read this abstract from Lane Beckes, James A. Coan, and Karen Hasselmo’s 2012 study, “Familiarity promotes the blurring of self and other in the neural representation of threat.” Neurobiological investigations of empathy often support an embodied simulation account. Using functional magnetic resonance imaging (fMRI), we monitored statistical associations between brain activations indicating self-focused threat to those indicating threats to a familiar friend or an unfamiliar stranger. Results in regions such as the anterior insula, putamen and supramarginal gyrus indicate that self-focused threat activations are robustly correlated with friend-focused threat activations but not stranger-focused threat activations. These results suggest that one of the defining features of human social bonding may be increasing levels of overlap between neural representations of self and other. This article presents a novel and important methodological approach to fMRI empathy studies, which informs how differences in brain activation can be detected in such studies and how covariate approaches can provide novel and important information regarding the brain and empathy. Did you recognize any of the concepts discussed in this module? This study used fMRI to examine the brain activation of people as they looked at cues and received, or were threatened with receiving, mild electric shocks while holding hands with either a friend or a stranger. The results showed the expected response—brain activation in the anterior insula, putamen, and supramarginal gyrus when a person was threatened with a shock. What was remarkable, however, was that people showed nearly the same brain activation when a friend was threatened with the shock, but not a stranger. This provides insight into studies on empathy, and the idea that the concept of “self” can expand to include others as well. As you can see, there is a limitless amount of information that could be studied on the brain. Neuroscience is a relatively new field, but the more research that is done, the more it appears that much of human behavior and mental processes—the key interests for psychological study—are intimately intertwined with activity in the brain. Understanding the brain is important no matter what type of psychology you will be involved with, because its effects permeate all human behavior. The more we learn about the brain and its functioning, the better able we are to work towards repairing the brain or mimicking its capabilities. These advances in research lead to medical discoveries and breakthroughs, such as the one explained in the following video: Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Modification, adaptation, and original content. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY-SA: Attribution-ShareAlike CC licensed content, Shared previouslyCC licensed content, Shared previously • Familiarity promotes the blurring of self and other in the neural representation of threat. Authored byAuthored by: Lane Beckes, James A. Coan, and Karen Hasselmo. Provided byProvided by: Oxford Academic. Located atLocated at: https://academic.oup.com/scan/article/8/6/670/1611749/Familiarity-promotes-the-blurring-of-self-and. ProjectProject: Social Cognitive and Affective Neuroscience (2012) 8 (6): 670-677. LicenseLicense: CC BY-NC: Attribution- NonCommercial • Psychology and the Brain. Provided byProvided by: Boundless. Located atLocated at: https://www.boundless.com/psychology/textbooks/boundless-psychology-textbook/biological-foundations-of-psychology-3/psychology-and-the-brain-406/ studying-the-brain-149-12684/. ProjectProject: Boundless Psychology. LicenseLicense: CC BY-SA: Attribution-ShareAlike All rights reserved contentAll rights reserved content • The nerve bypass: how to move a paralysed hand. Provided byProvided by: Nature. Located atLocated at: https://www.youtube.com/watch?v=60fAjaRfwnU. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License https://creativecommons.org/licenses/by-sa/4.0/ https://academic.oup.com/scan/article/8/6/670/1611749/Familiarity-promotes-the-blurring-of-self-and https://creativecommons.org/licenses/by-nc/4.0/ https://creativecommons.org/licenses/by-nc/4.0/ https://www.boundless.com/psychology/textbooks/boundless-psychology-textbook/biological-foundations-of-psychology-3/psychology-and-the-brain-406/studying-the-brain-149-12684/ https://www.boundless.com/psychology/textbooks/boundless-psychology-textbook/biological-foundations-of-psychology-3/psychology-and-the-brain-406/studying-the-brain-149-12684/ https://creativecommons.org/licenses/by-sa/4.0/ https://www.youtube.com/watch?v=60fAjaRfwnU DISCUSSION: BIOPSYCHOLOGY Using Your Brain Step 1Step 1: Write a discussion post of at least 150 words based on the following prompt (answer both questions): • Think of an activity you did today. Using what you learned in this module, describe at least five different parts of your brain and how they were involved in that activity. • If you were a psychologist or neuroscientist interested in learning more about one of those brain parts, what methods could you use to learn more about the brain? (Consider types of studies you could create, experiments you could design, brain-imaging techniques, and other methods described in your reading) Step 2Step 2: In a productive post that facilitates discussion, comment on at least TWO other posts with at least 75 words each. Add your own thoughts about the parts of the brain and methods used to study it. Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Using Your Brain Discussion: Biopsychology. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution https://creativecommons.org/licenses/by/4.0/ MODULE 4: SENSATION AND PERCEPTION WHY IT MATTERS: SENSATION AND PERCEPTION If you were standing in the midst of this street scene, you would be absorbing and processing numerous pieces of sensory input. (credit: modification of work by Cory Zanker) Imagine standing on a city street corner. You might be struck by movement everywhere as cars and people go about their business, by the sound of a street musician’s melody or a horn honking in the distance, by the smell of exhaust fumes or of food being sold by a nearby vendor, and by the sensation of hard pavement under your feet. We rely on our sensory systems to provide important information about our surroundings. We use this information to successfully navigate and interact with our environment so that we can find nourishment, seek shelter, maintain social relationships, and avoid potentially dangerous situations. But while sensory information is critical to our survival, there is so much information available at any given time that we would be overwhelmed if we were forced to attend to all of it. In fact, we are aware of only a fraction of the sensory information taken in by our sensory systems at any given time. This module will provide an overview of how sensory information is received and processed by the nervous system and how that affects our conscious experience of the world. We begin by learning the distinction between sensation and perception. Then we consider the physical properties of light and sound stimuli, along with an overview of the basic structure and function of the major sensory systems. The module will close with a discussion of a historically important theory of perception called the Gestalt theory. This theory attempts to explain some underlying principles of perception. AnswerAnswer Aaron, J. I., Mela, D. J., & Evans, R. E. (1994). The influences of attitudes, beliefs, and label information on perceptions of reduced-fat spread. Appetite, 22, 25–37. Abraira, V. E., & Ginty, D. D. (2013). The sensory neurons of touch. Neuron, 79, 618–639. Ayabe-Kanamura, S., Saito, S., Distel, H., Martínez-Gómez, M., & Hudson, R. (1998). Differences and similarities in the perception of everyday odors: A Japanese-German cross-cultural study. Annals of the New York Academy of Sciences, 855, 694–700. Chen, Q., Deng, H., Brauth, S. E., Ding, L., & Tang, Y. (2012). Reduced performance of prey targeting in pit vipers with contralaterally occluded infrared and visual senses. PloS ONE, 7(5), e34989. doi:10.1371/ journal.pone.0034989 Comfort, A. (1971). Likelihood of human pheromones. Nature, 230, 432–479. Correll, J., Park, B., Judd, C. M., & Wittenbrink, B. (2002). The police officer’s dilemma: Using ethnicity to disambiguate potentially threatening individuals. Journal of Personality and Social Psychology, 83, 1314–1329. Correll, J., Urland, G. R., & Ito, T. A. (2006). Event-related potentials and the decision to shoot: The role of threat perception and cognitive control. The Journal of Experimental Social Psychology, 42, 120–128. Dunkle T. (1982). The sound of silence. Science, 82, 30–33. Fawcett, S. L., Wang, Y., & Birch, E. E. (2005). The critical period for susceptibility of human stereopsis. Investigative Ophthalmology and Visual Science, 46, 521–525. Furlow, F. B. (1996, 2012). The smell of love. Retrieved from http://www.psychologytoday.com/articles/200910/ the-smell-love Galanter, E. (1962). Contemporary Psychophysics. In R. Brown, E.Galanter, E. H. Hess, & G. Mandler (Eds.), New directions in psychology. New York, NY: Holt, Rinehart & Winston. Garland, E. L. (2012). Pain processing in the human nervous system: A selective review of nociceptive and biobehavioral pathways. Primary Care, 39, 561–571. Goolkasian, P. & Woodbury, C. (2010). Priming effects with ambiguous figures. Attention, Perception & Psychophysics, 72, 168–178. Grothe, B., Pecka, M., & McAlpine, D. (2010). Mechanisms of sound localization in mammals. Physiological Reviews, 90, 983–1012. Hartline, P. H., Kass, L., & Loop, M. S. (1978). Merging of modalities in the optic tectum: Infrared and visual integration in rattlesnakes. Science, 199, 1225–1229. Kaiser, P. K. (1997). The joy of visual perception: A web book. Retrieved from http://www.yorku.ca/eye/ noframes.htm Khan, S., & Chang, R. (2013). Anatomy of the vestibular system: A review. NeuroRehabilitation, 32, 437–443. Kinnamon, S. C., & Vandenbeuch, A. (2009). Receptors and transduction of umami taste stimuli. Annals of the New York Academy of Sciences, 1170, 55–59. Kunst-Wilson, W. R., & Zajonc, R. B. (1980). Affective discrimination of stimuli that cannot be recognized. Science, 207, 557–558. Lackner, J. R., & DiZio, P. (2005). Vestibular, proprioceptive, and haptic contributions to spatial orientation. Annual Review of Psychology, 56, 115–147. Land, E. H. (1959). Color vision and the natural image. Part 1. Proceedings of the National Academy of Science, 45(1), 115–129. Liem, D. G., Westerbeek, A., Wolterink, S., Kok, F. J., & de Graaf, C. (2004). Sour taste preferences of children relate to preference for novel and intense stimuli. Chemical Senses, 29, 713–720. Lodovichi, C., & Belluscio, L. (2012). Odorant receptors in the formation of olfactory bulb circuitry. Physiology, 27, 200–212. Loersch, C., Durso, G. R. O., & Petty, R. E. (2013). Vicissitudes of desire: A matching mechanism for subliminal persuasion. Social Psychological and Personality Science, 4(5), 624–631. Maffei, A., Haley, M., & Fontanini, A. (2012). Neural processing of gustatory information in insular circuits. Current Opinion in Neurobiology, 22, 709–716. Milner, A. D., & Goodale, M. A. (2008). Two visual systems re-viewed. Neuropsychological, 46, 774–785. Mizushige, T., Inoue, K., Fushiki, T. (2007). Why is fat so tasty? Chemical reception of fatty acid on the tongue. Journal of Nutritional Science and Vitaminology, 53, 1–4. Most, S. B., Simons, D. J., Scholl, B. J., & Chabris, C. F. (2000). Sustained inattentional blindness: The role of location in the detection of unexpected dynamic events. PSYCHE, 6(14). Nelson, M. R. (2008). The hidden persuaders: Then and now. Journal of Advertising, 37(1), 113–126. Niimura, Y., & Nei, M. (2007). Extensive gains and losses of olfactory receptor genes in mammalian evolution. PLoS ONE, 2, e708. Okawa, H., & Sampath, A. P. (2007). Optimization of single-photon response transmission at the rod-to-rod bipolar synapse. Physiology, 22, 279–286. Payne, B. K. (2001). Prejudice and perception: The role of automatic and controlled processes in misperceiving a weapon. Journal of Personality and Social Psychology, 81, 181–192. Payne, B. K., Shimizu, Y., & Jacoby, L. L. (2005). Mental control and visual illusions: Toward explaining race- biased weapon misidentifications. Journal of Experimental Social Psychology, 41, 36–47. Peck, M. (2012, July 19). How a movie changed one man’s vision forever. Retrieved from http://www.bbc.com/ future/story/20120719-awoken-from-a-2d-world Peterson, M. A., & Gibson, B. S. (1994). Must figure-ground organization precede object recognition? An assumption in peril. Psychological Science, 5, 253–259. Petho, G., & Reeh, P. W. (2012). Sensory and signaling mechanisms of bradykinin, eicosanoids, platelet- activating factor, and nitric oxide in peripheral nociceptors. Physiological Reviews, 92, 1699–1775. Proske, U. (2006). Kinesthesia: The role of muscle receptors. Muscle & Nerve, 34, 545–558. Proske, U., & Gandevia, S. C. (2012). The proprioceptive senses: Their roles in signaling body shape, body position and movement, and muscle force. Physiological Reviews, 92, 1651–1697. Purvis, K., & Haynes, N. B. (1972). The effect of female rat proximity on the reproductive system of male rats. Physiology & Behavior, 9, 401–407. Radel, R., Sarrazin, P., Legrain, P., & Gobancé, L. (2009). Subliminal priming of motivational orientation in educational settings: Effect on academic performance moderated by mindfulness. Journal of Research in Personality, 43(4), 1–18. Rauschecker, J. P., & Tian, B. (2000). Mechanisms and streams for processing “what” and “where” in auditory cortex. Proceedings of the National Academy of Sciences, USA, 97, 11800–11806. Renier, L. A., Anurova, I., De Volder, A. G., Carlson, S., VanMeter, J., & Rauschecker, J. P. (2009). Multisensory integration of sounds and vibrotactile stimuli in processing streams for “what” and “where.” Journal of Neuroscience, 29, 10950–10960. Rensink, R. A. (2004). Visual sensing without seeing. Psychological Science, 15, 27–32. Rock, I., & Palmer, S. (1990). The legacy of Gestalt psychology. Scientific American, 262, 84–90. Roper, S. D. (2013). Taste buds as peripheral chemosensory receptors. Seminars in Cell & Developmental Biology, 24, 71–79. Russell, M. J. (1976). Human olfactory communication. Nature, 260, 520–522. Sachs, B. D. (1997). Erection evoked in male rats by airborne scent from estrous females. Physiology & Behavior, 62, 921–924. Segall, M. H., Campbell, D. T., & Herskovits, M. J. (1963). Cultural differences in the perception of geometric illusions. Science, 139, 769–771. Segall, M. H., Campbell, D. T., & Herskovits, M. J. (1966). The influence of culture on visual perception. Indianapolis: Bobbs-Merrill. Segall, M. H., Dasen, P. P., Berry, J. W., & Poortinga, Y. H. (1999). Human behavior in global perspective (2nd ed.). Boston: Allyn & Bacon. Semaan, M. T., & Megerian, C. A. (2010). Contemporary perspectives on the pathophysiology of Meniere’s disease: implications for treatment. Current opinion in Otolaryngology & Head and Neck Surgery, 18(5), 392–398. Shamma, S. (2001). On the role of space and time in auditory processing. Trends in Cognitive Sciences, 5, 340–348. Simons, D. J., & Chabris, C. F. (1999). Gorillas in our midst: Sustained inattentional blindness for dynamic events. Perception, 28, 1059–1074. Spors, H., Albeanu, D. F., Murthy, V. N., Rinberg, D., Uchida, N., Wachowiak, M., & Friedrich, R. W. (2013). Illuminating vertebrate olfactory processing. Journal of Neuroscience, 32, 14102–14108. Spray, D. C. (1986). Cutaneous temperature receptors. Annual Review of Physiology, 48, 625–638. Strain, G. M. (2003). How well do dogs and other animals hear? Retrieved from http://www.lsu.edu/deafness/ HearingRange.html Swets, J. A. (1964). Signal detection and recognition by human observers. Psychological Bulletin, 60, 429–441. Ungerleider, L. G., & Haxby, J. V. (1994). ‘What’ and ‘where’ in the human brain. Current Opinion in Neurobiology, 4, 157–165. U.S. National Library of Medicine. (2013). Genetics home reference: Congenital insensitivity to pain. Retrieved from http://ghr.nlm.nih.gov/condition/congenital-insensitivity-to-pain Vecera, S. P., & O’Reilly, R. C. (1998). Figure-ground organization and object recognition processes: An interactive account. Journal of Experimental Psychology-Human Perception and Performance, 24, 441–462. Wakakuwa, M., Stavenga, D. G., & Arikawa, K. (2007). Spectral organization of ommatidia in flower-visiting insects. Photochemistry and Photobiology, 83, 27–34. Weller, A. (1998). Human pheromones: Communication through body odour. Nature, 392, 126–127. Wells, D. L. (2010). Domestic dogs and human health: An overview. British Journal of Health Psychology, 12, 145–156. Wolfgang-Kimball, D. (1992). Pheromones in humans: myth or reality?. Retrieved from http://www.anapsid.org/ pheromones.html Wysocki, C. J., & Preti, G. (2004). Facts, fallacies, fears, and frustrations with human pheromones. The Anatomical Record Part A: Discoveries in Molecular, Cellular, and Evolutionary Biology, 281, 1201–1211. Licensing & AttributionsLicensing & Attributions CC licensed content, Shared previouslyCC licensed content, Shared previously • Introduction to Sensation and Perception. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.49:SPm67RdT@6/Introduction. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/content/col11629/latest/. SENSATION AND PERCEPTION What you’ll learn to do: differentiate between sensation and perception Sensation and perception are two separate processes that are very closely related. Sensation is input about the physical world obtained by our sensory receptors, and perception is the process by which the brain selects, organizes, and interprets these sensations. In other words, senses are the physiological basis of perception. Perception of the same senses may vary from one person to another because each person’s brain interprets stimuli differently based on that individual’s learning, memory, emotions, and expectations. LEARNING OBJECTIVESLEARNING OBJECTIVES • Define sensation and explain its connection to the concepts of absolute threshold, difference threshold, and subliminal messages • Discuss the roles attention, motivation, and sensory adaptation play in perception http://cnx.org/contents/Sr8Ev5Og@5.49:SPm67RdT@6/Introduction https://creativecommons.org/licenses/by/4.0/ https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/02/02212759/Signac_-_Portrait_de_Fe%CC%81lix_Fe%CC%81ne%CC%81on Figure 1. The absolute threshold for detecting light is greater than you probably imagined—the human eye can see a candle on a clear night up to 30 miles away! Sensation What does it mean to sense something? Sensory receptors are specialized neurons that respond to specific types of stimuli. When sensory information is detected by a sensory receptor, sensationsensation has occurred. For example, light that enters the eye causes chemical changes in cells that line the back of the eye. These cells relay messages, in the form of action potentials (as you learned when studying biopsychology), to the central nervous system. The conversion from sensory stimulus energy to action potential is known as transductiontransduction. You have probably known since elementary school that we have five senses: vision, hearing (audition), smell (olfaction), taste (gustation), and touch (somatosensation). It turns out that this notion of five senses is oversimplified. We also have sensory systems that provide information about balance (the vestibular sense), body position and movement (proprioception and kinesthesia), pain (nociception), and temperature (thermoception). The sensitivity of a given sensory system to the relevant stimuli can be expressed as an absolute threshold. Absolute thresholdAbsolute threshold refers to the minimum amount of stimulus energy that must be present for the stimulus to be detected 50% of the time. Another way to think about this is by asking how dim can a light be or how soft can a sound be and still be detected half of the time. The sensitivity of our sensory receptors can be quite amazing. It has been estimated that on a clear night, the most sensitive sensory cells in the back of the eye can detect a candle flame 30 miles away (Okawa & Sampath, 2007). Under quiet conditions, the hair cells (the receptor cells of the inner ear) can detect the tick of a clock 20 feet away (Galanter, 1962). It is also possible for us to get messages that are presented below the threshold for conscious awareness—these are called subliminal messagessubliminal messages. A stimulus reaches a physiological threshold when it is strong enough to excite sensory receptors and send nerve impulses to the brain: This is an absolute threshold. A message below that threshold is said to be subliminal: We receive it, but we are not consciously aware of it. Over the years there has been a great deal of speculation about the use of subliminal messages in advertising, rock music, and self-help audio programs. Research evidence shows that in laboratory settings, people can process and respond to information outside of awareness. But this does not mean that we obey these messages like zombies; in fact, hidden messages have little effect on behavior outside the laboratory (Kunst-Wilson & Zajonc, 1980; Rensink, 2004; Nelson, 2008; Radel, Sarrazin, Legrain, & Gobancé, 2009; Loersch, Durso, & Petty, 2013). https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/01/26190242/3631956828_1a4c9c4d93_z https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/01/26190242/3631956828_1a4c9c4d93_z Figure 2. Priming can be used to improve intellectual test performance. Research subjects primed with the stereotype of a professor – a sort of intellectual role model – outperformed those primed with an anti- intellectual stereotype. [Photo: Jeremy Wilburn] DIG DEEPER: UNCONSCIOUS PERCEPTIONDIG DEEPER: UNCONSCIOUS PERCEPTION These days, most scientific research on unconscious processes is aimed at showing that people do not need consciousness for certain psychological processes or behaviors. One such example is attitude formation. The most basic process of attitude formation is through mere exposure (Zajonc, 1968). Merely perceiving a stimulus repeatedly, such as a brand on a billboard one passes every day or a song that is played on the radio frequently, renders it more positive. Interestingly, mere exposure does not require conscious awareness of the object of an attitude. In fact, mere-exposure effectsmere-exposure effects occur even when novel stimuli are presented subliminally for extremely brief durations (e.g., Kunst-Wilson & Zajonc, 1980). Intriguingly, in such subliminal mere-exposure experiments, participants indicate a preference for, or a positive attitude towards, stimuli they do not consciously remember being exposed to. Another example of modern research on unconscious processes is research on primingpriming. In a well-known experiment by a research team led by the American psychologist John Bargh (Bargh, Chen, & Burrows, 1996), half the participants were primed with the stereotype of the elderly by doing a language task (they had to make sentences on the basis of lists of words). These lists contained words commonly associated with the elderly (e.g., “old,” “bingo,” “walking stick,” “Florida”). The remaining participants received a language task in which the critical words were replaced by words not related to the elderly. After participants had finished they were told the experiment was over, but they were secretly monitored to see how long they took to walk to the nearest elevator. The primed participants took significantly longer. That is, after being exposed to words typically associated with being old, they behaved in line with the stereotype of old people: being slow.Such priming effects have been shown in many different domains. For example, Dijksterhuis and van Knippenberg (1998) demonstrated that priming can improve intellectual performance. They asked their participants to answer 42 general knowledge questions taken from the game Trivial Pursuit. Under normal conditions, participants answered about 50% of the questions correctly. However, participants primed with the stereotype of professors—who are by most people seen as intelligent—managed to answer 60% of the questions correctly. Conversely, performance of participants primed with the “dumb” stereotype of hooligans dropped to 40%. TRY ITTRY IT Absolute thresholds are generally measured under incredibly controlled conditions in situations that are optimal for sensitivity. Sometimes, we are more interested in how much difference in stimuli is required to detect a difference between them. This is known as the just noticeable difference (jnd)just noticeable difference (jnd) or difference thresholddifference threshold. Unlike the absolute threshold, the difference threshold changes depending on the stimulus intensity. As an example, imagine yourself in a very dark movie theater. If an audience member were to receive a text message on her cell phone which caused her screen to light up, chances are that many people would notice the change in illumination in the theater. However, if the same thing happened in a brightly lit arena during a basketball game, very few people would notice. The cell phone brightness does not change, but its ability to be detected as a change in illumination varies dramatically between the two contexts. Ernst Weber proposed this theory of change in difference threshold in the 1830s, and it has become known as Weber’s lawWeber’s law: The difference threshold is a constant fraction of the original stimulus, as the example illustrates. It is the idea that bigger stimuli require larger differences to be noticed. For example, it will be much harder for your friend to reliably tell the difference between 10 and 11 lbs. (or 5 versus 5.5 kg) than it is for 1 and 2 lbs. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/01/26185844/prof https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/01/26185844/prof An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2109 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2109 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2109 THINK IT OVERTHINK IT OVER Think about a time when you failed to notice something around you because your attention was focused elsewhere. If someone pointed it out, were you surprised that you hadn’t noticed it right away? Perception While our sensory receptors are constantly collecting information from the environment, it is ultimately how we interpret that information that affects how we interact with the world. PerceptionPerception refers to the way sensory information is organized, interpreted, and consciously experienced. Perception involves both bottom-up and top- down processing. Bottom-up processingBottom-up processing refers to the fact that perceptions are built from sensory input. On the other hand, how we interpret those sensations is influenced by our available knowledge, our experiences, and our thoughts. This is called top-down processingtop-down processing. Look at the shape in Figure 1 below. Seen alone, your brain engages in bottom-up processing. There are two thick vertical lines and three thin horizontal lines. There is no context to give it a specific meaning, so there is no top-down processing involved. Figure 3. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/01/26161444/Screen-Shot-2017-01-26-at-10.13.34-AM https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/01/26161444/Screen-Shot-2017-01-26-at-10.13.34-AM Now, look at the same shape in two different contexts. Surrounded by sequential letters, your brain expects the shape to be a letter and to complete the sequence. In that context, you perceive the lines to form the shape of the letter “B.” Figure 4. Surrounded by numbers, the same shape now looks like the number “13.” Figure 5. When given a context, your perception is driven by your cognitive expectations. Now you are processing the shape in a top-down fashion. One way to think of this concept is that sensation is a physical process, whereas perception is psychological. For example, upon walking into a kitchen and smelling the scent of baking cinnamon rolls, the sensation is the scent receptors detecting the odor of cinnamon, but the perception may be “Mmm, this smells like the bread Grandma used to bake when the family gathered for holidays.” An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2109 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2109 TRY ITTRY IT LINK TO LEARNINGLINK TO LEARNING See for yourself how inattentional blindness works by watching this selective attention test from Simons and Chabris (1999): LINK TO LEARNINGLINK TO LEARNING Read more on inattentional blindness though this link to the Noba Project website. Although our perceptions are built from sensations, not all sensations result in perception. In fact, we often don’t perceive stimuli that remain relatively constant over prolonged periods of time. This is known as sensorysensory adaptationadaptation. Imagine entering a classroom with an old analog clock. Upon first entering the room, you can hear the ticking of the clock; as you begin to engage in conversation with classmates or listen to your professor greet the class, you are no longer aware of the ticking. The clock is still ticking, and that information is still affecting sensory receptors of the auditory system. The fact that you no longer perceive the sound demonstrates sensory adaptation and shows that while closely associated, sensation and perception are different. Attention and Perception There is another factor that affects sensation and perception: attention. Attention plays a significant role in determining what is sensed versus what is perceived. Imagine you are at a party full of music, chatter, and laughter. You get involved in an interesting conversation with a friend, and you tune out all the background noise. If someone interrupted you to ask what song had just finished playing, you would probably be unable to answer that question. One of the most interesting demonstrations of how important attention is in determining our perception of the environment occurred in a famous study conducted by Daniel Simons and Christopher Chabris (1999). In this study, participants watched a video of people dressed in black and white passing basketballs. Participants were asked to count the number of times the team in white passed the ball. During the video, a person dressed in a black gorilla costume walks among the two teams. You would think that someone would notice the gorilla, right? Nearly half of the people who watched the video didn’t notice the gorilla at all, despite the fact that he was clearly visible for nine seconds. Because participants were so focused on the number of times the white team was passing the ball, they completely tuned out other visual information. Failure to notice something that is completely visible because of a lack of attention is called inattentional blindnessinattentional blindness. In a similar experiment, researchers tested inattentional blindness by asking participants to observe images moving across a computer screen. They were instructed to focus on either white or black objects, disregarding the other color. When a red cross passed across the screen, about one third of subjects did not notice it (Figure 4) (Most, Simons, Scholl, & Chabris, 2000). http://nobaproject.com/modules/failures-of-awareness-the-case-of-inattentional-blindness A YouTube element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2109 Figure 6. Nearly one third of participants in a study did not notice that a red cross passed on the screen because their attention was focused on the black or white figures. (credit: Cory Zanker) Motivations, Expectations, and Perception Motivation can also affect perception. Have you ever been expecting a really important phone call and, while taking a shower, you think you hear the phone ringing, only to discover that it is not? If so, then you have experienced how motivation to detect a meaningful stimulus can shift our ability to discriminate between a true sensory stimulus and background noise. The ability to identify a stimulus when it is embedded in a distracting background is called signal detection theorysignal detection theory. This might also explain why a mother is awakened by a quiet murmur from her baby but not by other sounds that occur while she is asleep. Signal detection theory has practical applications, such as increasing air traffic controller accuracy. Controllers need to be able to detect planes among many signals (blips) that appear on the radar screen and follow those planes as they move through the sky. In fact, the original work of the researcher who developed signal detection theory was focused on improving the sensitivity of air traffic controllers to plane blips (Swets, 1964). Our perceptions can also be affected by our beliefs, values, prejudices, expectations, and life experiences. As you will see later in this module, individuals who are deprived of the experience of binocular vision during critical periods of development have trouble perceiving depth (Fawcett, Wang, & Birch, 2005). The shared experiences of people within a given cultural context can have pronounced effects on perception. For example, Marshall Segall, Donald Campbell, and Melville Herskovits (1963) published the results of a multinational study in which they demonstrated that individuals from Western cultures were more prone to experience certain types of visual illusions than individuals from non-Western cultures, and vice versa. One such illusion that Westerners were more likely to experience was the Müller-Lyer illusionMüller-Lyer illusion (Figure 5): The lines appear to be different lengths, but they are actually the same length. Figure 7. In the Müller-Lyer illusion, lines appear to be different lengths although they are identical. (a) Arrows at the ends of lines may make the line on the right appear longer, although the lines are the same length. (b) When applied to a three-dimensional image, the line on the right again may appear longer although both black lines are the same length. LINK TO LEARNINGLINK TO LEARNING If you want to learn more about the differences between sensation and perception, you can review in this CrashCourse Psychology video: An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2109 TRY ITTRY IT These perceptual differences were consistent with differences in the types of environmental features experienced on a regular basis by people in a given cultural context. People in Western cultures, for example, have a perceptual context of buildings with straight lines, what Segall’s study called a carpentered world (Segall et al., 1966). In contrast, people from certain non-Western cultures with an uncarpentered view, such as the Zulu of South Africa, whose villages are made up of round huts arranged in circles, are less susceptible to this illusion (Segall et al., 1999). It is not just vision that is affected by cultural factors. Indeed, research has demonstrated that the ability to identify an odor, and rate its pleasantness and its intensity, varies cross-culturally (Ayabe-Kanamura, Saito, Distel, Martínez-Gómez, & Hudson, 1998). Children described as thrill seekers are more likely to show taste preferences for intense sour flavors (Liem, Westerbeek, Wolterink, Kok, & de Graaf, 2004), which suggests that basic aspects of personality might affect perception. Furthermore, individuals who hold positive attitudes toward reduced-fat foods are more likely to rate foods labeled as reduced fat as tasting better than people who have less positive attitudes about these products (Aaron, Mela, & Evans, 1994). A YouTube element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2109 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2109 GLOSSARYGLOSSARY absolute threshold:absolute threshold: minimum amount of stimulus energy that must be present for the stimulus to be detected 50% of the time bottom-up processing:bottom-up processing: system in which perceptions are built from sensory input inattentional blindness:inattentional blindness: failure to notice something that is completely visible because of a lack of attention just noticeable difference:just noticeable difference: difference in stimuli required to detect a difference between the stimuli mere-exposure effectsmere-exposure effects: the result of developing a more positive attitude towards a stimulus after repeated instances of mere exposure to it. THINK IT OVERTHINK IT OVER Think about a time when you failed to notice something around you because your attention was focused elsewhere. If someone pointed it out, were you surprised that you hadn’t noticed it right away? perception:perception: way that sensory information is interpreted and consciously experienced primingpriming: the process by which recent experiences increase a trait’s accessibility. sensation:sensation: what happens when sensory information is detected by a sensory receptor signal detection theory:signal detection theory: change in stimulus detection as a function of current mental state subliminal message:subliminal message: message presented below the threshold of conscious awareness top-down processing:top-down processing: interpretation of sensations is influenced by available knowledge, experiences, and thoughts transduction:transduction: conversion from sensory stimulus energy to action potential An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2109 Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Modification, adaptation, and original content. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution CC licensed content, Shared previouslyCC licensed content, Shared previously • Sensation versus Perception. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.52:K-DZ-03P@5/Sensation-versus-Perception. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/contents/4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@5.48 • Introduction to Sensation. Provided byProvided by: Boundless. Located atLocated at: https://www.boundless.com/psychology/textbooks/boundless-psychology-textbook/sensation-and-perception-5/introduction-to-sensation-37/introduction- to-sensation-157-12692/. ProjectProject: Boundless Psychology. LicenseLicense: CC BY-SA: Attribution-ShareAlike • Dig Deeper on the Unconscious and image. Authored byAuthored by: Ap Dijksterhuis Radboud. Provided byProvided by: University Nijmegen. Located atLocated at: http://nobaproject.com/modules/the-unconscious. ProjectProject: The Noba Project. LicenseLicense: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike • Sensation and Perception, last example on Weber's Law. Authored byAuthored by: Adam John Privitera. Provided byProvided by: Chemeketa Community College. Located atLocated at: http://nobaproject.com/modules/sensation-and-perception. ProjectProject: The Noba Project. LicenseLicense: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike • Candle in the dark. Authored byAuthored by: pratanti. Provided byProvided by: Flickr. Located atLocated at: https://www.flickr.com/photos/pratanti/3631956828. LicenseLicense: CC BY: Attribution • Section on bottom-up versus top-down processing. Authored byAuthored by: Dr. Scott Roberts, Dr. Ryan Curtis, Samantha Levy, and Dr. Dylan Selterman. Provided byProvided by: OpenPsyc. Located atLocated at: http://openpsyc.blogspot.com/2014/06/ bottom-up-vs-top-down-processing.html. LicenseLicense: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike All rights reserved contentAll rights reserved content • Sensation & Perception - Crash Course Psychology #5. Provided byProvided by: CrashCourse. Located atLocated at: https://www.youtube.com/watch?v=unWnZvXJH2o. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License Public domain contentPublic domain content • Painting. Authored byAuthored by: Paul Signac. Provided byProvided by: Wikimedia. Located atLocated at: https://en.wikipedia.org/wiki/Soci%C3%A9t%C3%A9_des_Artistes_Ind%C3%A9pendants#/media/File:Signac_- _Portrait_de_F%C3%A9lix_F%C3%A9n%C3%A9on . LicenseLicense: Public Domain: No Known Copyright https://creativecommons.org/licenses/by/4.0/ http://cnx.org/contents/Sr8Ev5Og@5.52:K-DZ-03P@5/Sensation-versus-Perception https://creativecommons.org/licenses/by/4.0/ https://www.boundless.com/psychology/textbooks/boundless-psychology-textbook/sensation-and-perception-5/introduction-to-sensation-37/introduction-to-sensation-157-12692/ https://www.boundless.com/psychology/textbooks/boundless-psychology-textbook/sensation-and-perception-5/introduction-to-sensation-37/introduction-to-sensation-157-12692/ https://creativecommons.org/licenses/by-sa/4.0/ http://nobaproject.com/modules/the-unconscious https://creativecommons.org/licenses/by-nc-sa/4.0/ https://creativecommons.org/licenses/by-nc-sa/4.0/ http://nobaproject.com/modules/sensation-and-perception https://creativecommons.org/licenses/by-nc-sa/4.0/ https://www.flickr.com/photos/pratanti/3631956828 https://creativecommons.org/licenses/by/4.0/ http://openpsyc.blogspot.com/2014/06/bottom-up-vs-top-down-processing.html http://openpsyc.blogspot.com/2014/06/bottom-up-vs-top-down-processing.html https://creativecommons.org/licenses/by-nc-sa/4.0/ https://www.youtube.com/watch?v=unWnZvXJH2o https://en.wikipedia.org/wiki/Soci%C3%A9t%C3%A9_des_Artistes_Ind%C3%A9pendants#/media/File:Signac_-_Portrait_de_F%C3%A9lix_F%C3%A9n%C3%A9on https://en.wikipedia.org/wiki/Soci%C3%A9t%C3%A9_des_Artistes_Ind%C3%A9pendants#/media/File:Signac_-_Portrait_de_F%C3%A9lix_F%C3%A9n%C3%A9on https://creativecommons.org/about/pdm Our eyes take in sensory information that helps us understand the world around us. (credit “top left”: modification of work by “rajkumar1220″/Flickr”; credit “top right”: modification of work by Thomas Leuthard; credit “middle left”: modification of work by Demietrich Baker; credit “middle right”: modification of work by “kaybee07″/Flickr; credit “bottom left”: modification of work by “Isengardt”/Flickr; credit “bottom right”: modification of work by Willem Heerbaart) VISION What you’ll learn to do: explain the process of vision and how people see color and depth The visual system constructs a mental representation of the world around us. This contributes to our ability to successfully navigate through physical space and interact with important individuals and objects in our environments. This section will provide an overview of the basic anatomy and function of the visual system. In addition, you’ll explore our ability to perceive color and depth. LEARNING OBJECTIVESLEARNING OBJECTIVES • Describe the basic anatomy of the visual system • Describe how light waves enable vision • Describe the trichromatic theory of color vision and the opponent-process theory • Describe how monocular and binocular cues are used in the perception of depth Figure 1. The anatomy of the eye is illustrated in this diagram. Anatomy of the Visual System The eye is the major sensory organ involved in visionvision (Figure 1). Light waves are transmitted across the cornea and enter the eye through the pupil. The corneacornea is the transparent covering over the eye. It serves as a barrier between the inner eye and the outside world, and it is involved in focusing light waves that enter the eye. The pupilpupil is the small opening in the eye through which light passes, and the size of the pupil can change as a function of light levels as well as emotional arousal. When light levels are low, the pupil will become dilated, or expanded, to allow more light to enter the eye. When light levels are high, the pupil will constrict, or become smaller, to reduce the amount of light that enters the eye. The pupil’s size is controlled by muscles that are connected to the irisiris, which is the colored portion of the eye. After passing through the pupil, light crosses the lenslens, a curved, transparent structure that serves to provide additional focus. The lens is attached to muscles that can change its shape to aid in focusing light that is reflected from near or far objects. In a normal-sighted individual, the lens will focus images perfectly on a small indentation in the back of the eye known as the foveafovea, which is part of the retinaretina, the light-sensitive lining of the eye. The fovea contains densely packed specialized photoreceptor cells (Figure 2). These photoreceptorphotoreceptor cells, known as conescones, are light-detecting cells. The cones are specialized types of photoreceptors that work best in bright light conditions. Cones are very sensitive to acute detail and provide tremendous spatial resolution. They also are directly involved in our ability to perceive color. While cones are concentrated in the fovea, where images tend to be focused, rods, another type of photoreceptor, are located throughout the remainder of the retina. RodsRods are specialized photoreceptors that work well in low light conditions, and while they lack the spatial resolution and color function of the cones, they are involved in our vision in dimly lit environments as well as in our perception of movement on the periphery of our visual field. Figure 2. The two types of photoreceptors are shown in this image. Rods are colored green and cones are blue. We have all experienced the different sensitivities of rods and cones when making the transition from a brightly lit environment to a dimly lit environment. Imagine going to see a blockbuster movie on a clear summer day. As you walk from the brightly lit lobby into the dark theater, you notice that you immediately have difficulty seeing much of anything. After a few minutes, you begin to adjust to the darkness and can see the interior of the theater. In the bright environment, your vision was dominated primarily by cone activity. As you move to the dark environment, rod activity dominates, but there is a delay in transitioning between the phases. If your rods do not transform light into nerve impulses as easily and efficiently as they should, you will have difficulty seeing in dim light, a condition known as night blindness. Rods and cones are connected (via several interneurons) to retinal ganglion cells. Axons from the retinal ganglion cells converge and exit through the back of the eye to form the optic nerve. The optic nerveoptic nerve carries visual information from the retina to the brain. There is a point in the visual field called the blind spotblind spot: Even when light from a small object is focused on the blind spot, we do not see it. We are not consciously aware of our blind spots for two reasons: First, each eye gets a slightly different view of the visual field; therefore, the blind spots do not overlap. Second, our visual system fills in the blind spot so that although we cannot respond to visual information that occurs in that portion of the visual field, we are also not aware that information is missing. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2111 TRY ITTRY IT Figure 3. This illustration shows the optic chiasm at the front of the brain and the pathways to the occipital lobe at the back of the brain, where visual sensations are processed into meaningful perceptions. The optic nerve from each eye merges just below the brain at a point called the optic chiasmoptic chiasm. As Figure 3 shows, the optic chiasm is an X-shaped structure that sits just below the cerebral cortex at the front of the brain. At the point of the optic chiasm, information from the right visual field (which comes from both eyes) is sent to the left side of the brain, and information from the left visual field is sent to the right side of the brain. Once inside the brain, visual information is sent via a number of structures to the occipital lobe at the back of the brain for processing. Visual information might be processed in parallel pathways which can generally be described as the “what pathway” (the ventral pathway) and the “where/how” pathway (the dorsal pathway). The “what pathway” is involved in object recognition and identification, while the “where/how pathway” is involved with location in space and how one might interact with a particular visual stimulus (Milner & Goodale, 2008; Ungerleider & Haxby, 1994). For example, when you see a ball rolling down the street, the “what pathway” identifies what the object is, and the “where/how pathway” identifies its location or movement in space. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2111 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2111 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2111 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2111 TRY ITTRY IT Figure 4. Visual areas in the brain. Amplitude and Wavelength As mentioned above, light enters your eyes as a wave. It is important to understand some basic properties of waves to see how they impact what we see. Two physical characteristics of a wave are amplitudeamplitude and wavelength (Figure 5). The amplitude of a wave is the height of a wave as measured from the highest point on the wavewave (peakpeak or crestcrest) to the lowest point on the wave (trough). WavelengthWavelength refers to the length of a wave from one peak to the next. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/10/26200309/visualpathways https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/10/26200309/visualpathways Figure 5. The amplitude or height of a wave is measured from the peak to the trough. The wavelength is measured from peak to peak. Figure 6. This figure illustrates waves of differing wavelengths/frequencies. At the top of the figure, the red wave has a long wavelength/short frequency. Moving from top to bottom, the wavelengths decrease and frequencies increase. Wavelength is directly related to the frequency of a given wave form. FrequencyFrequency refers to the number of waves that pass a given point in a given time period and is often expressed in terms of hertz (Hzhertz (Hz), or cycles per second. Longer wavelengths will have lower frequencies, and shorter wavelengths will have higher frequencies (Figure 6). Light Waves The visible spectrumvisible spectrum is the portion of the larger electromagnetic spectrum that we can see. As Figure 7 shows, the electromagnetic spectrumelectromagnetic spectrum encompasses all of the electromagnetic radiation that occurs in our environment and includes gamma rays, x-rays, ultraviolet light, visible light, infrared light, microwaves, and radio waves. The visible spectrum in humans is associated with wavelengths that range from 380 to 740 nm—a very small distance, since a nanometer (nm) is one billionth of a meter. Other species can detect other portions of the electromagnetic spectrum. For instance, honeybees can see light in the ultraviolet range (Wakakuwa, Stavenga, & Arikawa, 2007), and some snakes can detect infrared radiation in addition to more traditional visual light cues (Chen, Deng, Brauth, Ding, & Tang, 2012; Hartline, Kass, & Loop, 1978). Figure 7. Light that is visible to humans makes up only a small portion of the electromagnetic spectrum. Figure 8. Different wavelengths of light are associated with our perception of different colors. (credit: modification of work by Johannes Ahlmann) An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2111 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2111 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2111 TRY ITTRY IT In humans, light wavelength is associated with perception of color (Figure 8). Within the visible spectrum, our experience of red is associated with longer wavelengths, greens are intermediate, and blues and violets are shorter in wavelength. (An easy way to remember this is the mnemonic ROYGBIV: rred, oorange, yyellow, ggreen, bblue, iindigo, vviolet.) The amplitude of light waves is associated with our experience of brightness or intensity of color, with larger amplitudes appearing brighter. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2111 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2111 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2111 We do not see the world in black and white; neither do we see it as two-dimensional (2-D) or flat (just height and width, no depth). Let’s look at how color vision works and how we perceive three dimensions (height, width, and depth). Color Vision Normal-sighted individuals have three different types of cones that mediate color visioncolor vision. Each of these cone types is maximally sensitive to a slightly different wavelength of light. According to the Young-Helmholtz trichromatictrichromatic theory of color visiontheory of color vision, shown in Figure 9, all colors in the spectrum can be produced by combining red, green, and blue. The three types of cones are each receptive to one of the colors. Figure 9. This figure illustrates the different sensitivities for the three cone types found in a normal-sighted individual. (credit: modification of work by Vanessa Ezekowitz) The trichromatic theory of color vision is not the only theory—another major theory of color vision is known as the opponent-process theoryopponent-process theory. According to this theory, color is coded in opponent pairs: black-white, yellow-blue, and green-red. The basic idea is that some cells of the visual system are excited by one of the opponent colors and inhibited by the other. So, a cell that was excited by wavelengths associated with green would be inhibited by wavelengths associated with red, and vice versa. One of the implications of opponent processing is that we do not experience greenish-reds or yellowish-blues as colors. Another implication is that this leads to the experience of negative afterimages. An afterimageafterimage describes the continuation of a visual sensation after removal of the stimulus. For example, when you stare briefly at the sun and then look away from it, you may still perceive a spot of light although the stimulus (the sun) has been removed. When color is involved in the stimulus, the color pairings identified in the opponent-process theory lead to a negative afterimage. You can test this concept using the flag in Figure 10. Figure 10. Stare at the white dot for 30–60 seconds and then move your eyes to a blank piece of white paper. What do you see? This is known as a negative afterimage, and it provides empirical support for the opponent-process theory of color vision. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2111 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2111 TRY ITTRY IT But these two theories—the trichromatic theory of color vision and the opponent-process theory—are not mutually exclusive. Research has shown that they just apply to different levels of the nervous system. For visual processing on the retina, trichromatic theory applies: the cones are responsive to three different wavelengths that represent red, blue, and green. But once the signal moves past the retina on its way to the brain, the cells respond in a way consistent with opponent-process theory (Land, 1959; Kaiser, 1997). An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2111 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2111 Depth Perception Our ability to perceive spatial relationships in three-dimensional (3-D) space is known as depth perceptiondepth perception. With depth perception, we can describe things as being in front, behind, above, below, or to the side of other things. Our world is three-dimensional, so it makes sense that our mental representation of the world has three- dimensional properties. We use a variety of cues in a visual scene to establish our sense of depth. Some of these are binocular cuesbinocular cues, which means that they rely on the use of both eyes. One example of a binocular depth cue is binocular disparitybinocular disparity, the slightly different view of the world that each of our eyes receives. To experience this slightly different view, do this simple exercise: extend your arm fully and extend one of your fingers and focus on that finger. Now, close your left eye without moving your head, then open your left eye and close your right eye without moving your head. You will notice that your finger seems to shift as you alternate between the two eyes because of the slightly different view each eye has of your finger. A 3-D movie works on the same principle: the special glasses you wear allow the two slightly different images projected onto the screen to be seen separately by your left and your right eye. As your brain processes these images, you have the illusion that the leaping animal or running person is coming right toward you. Although we rely on binocular cues to experience depth in our 3-D world, we can also perceive depth in 2-D arrays. Think about all the paintings and photographs you have seen. Generally, you pick up on depth in these images even though the visual stimulus is 2-D. When we do this, we are relying on a number of monocular cuesmonocular cues, or cues that require only one eye. If you think you can’t see depth with one eye, note that you don’t bump into things when using only one eye while walking—and, in fact, we have more monocular cues than binocular cues. The following video of anamorphic art demonstrates how we rely on these monocular cues to see depth, even when the depth is only imagined. A YouTube element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2111 An example of a monocular cue would be what is known as linear perspectivelinear perspective. Linear perspective refers to the fact that we perceive depth when we see two parallel lines that seem to converge in an image (Figure 11). Some other monocular depth cues are interposition, the partial overlap of objects, the relative size and closeness of images to the horizon, relative size, and the variation between light and shadow. Figure 11. We perceive depth in a two-dimensional figure like this one through the use of monocular cues like linear perspective, like the parallel lines converging as the road narrows in the distance. (credit: Marc Dalmulder) DIG DEEPER: STEREOBLINDNESSDIG DEEPER: STEREOBLINDNESS Bruce Bridgeman was born with an extreme case of lazy eye that resulted in him being stereoblind, or unable to respond to binocular cues of depth. He relied heavily on monocular depth cues, but he never had a true appreciation of the 3-D nature of the world around him. This all changed one night in 2012 while Bruce was seeing a movie with his wife. The movie the couple was going to see was shot in 3-D, and even though he thought it was a waste of money, Bruce paid for the 3-D glasses when he purchased his ticket. As soon as the film began, Bruce put on the glasses and experienced something completely new. For the first time in his life he appreciated the true depth of the world around him. Remarkably, his ability to perceive depth persisted outside of the movie theater. There are cells in the nervous system that respond to binocular depth cues. Normally, these cells require activation during early development in order to persist, so experts familiar with Bruce’s case (and others like his) assume that at some point in his development, Bruce must have experienced at least a fleeting moment of binocular vision. It was enough to ensure the survival of the cells in the visual system tuned to binocular cues. The mystery now is why it took Bruce nearly 70 years to have these cells activated (Peck, 2012). TRY ITTRY IT An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2111 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2111 Photos in this activity from of GlacierNPS, Alicia Nijdam, KlipschFan, scillystuff, rhondawebber (CC-BY-2.0) LINK TO LEARNINGLINK TO LEARNING All of this talk about vision may have you wondering what this has to do with psychology. Remember that sensation is input about the physical world obtained by our sensory receptors, and perception is the process by which the brain selects, organizes, and interprets these sensations. In other words, senses are the physiological basis of perception. Perception of the same senses may vary from one person to another because each person’s brain interprets stimuli differently based on that individual’s learning, memory, emotions, and expectations. It is for this reason that psychologists study sensation—in order to understand perception, which is clearly a component of behavior and mental processes (the definition of psychology). To see this all in action, visit the BBC website HERE to participate in the sensation lab. Complete the twenty exercises and click on the “explanation” after each question to learn about how our senses are easily fooled. Integration with Other Modalities Vision is not an encapsulated system. It interacts with and depends on other sensory modalities. For example, when you move your head in one direction, your eyes reflexively move in the opposite direction to compensate, allowing you to maintain your gaze on the object that you are looking at. This reflex is called the vestibulo-ocularvestibulo-ocular reflexreflex. It is achieved by integrating information from both the visual and the vestibular system (which knows about body motion and position). You can experience this compensation quite simply. First, while you keep your head still and your gaze looking straight ahead, wave your finger in front of you from side to side. Notice how the image of the finger appears blurry. Now, keep your finger steady and look at it while you move your head from side to side. Notice how your eyes reflexively move to compensate the movement of your head and how the image of the finger stays sharp and stable. Vision also interacts with your proprioceptive system, to help you find where all your body parts are, and with your auditory system, to help you understand the sounds people make when they speak. You can learn more about this in the multimodal module. Finally, vision is also often implicated in a blending-of-sensations phenomenon known as synesthesiasynesthesia. Synesthesia occurs when one sensory signal gives rise to two or more sensations. The most common type is grapheme-color synesthesia. About 1 in 200 individuals experience a sensation of color associated with specific letters, numbers, or words: the number 1 might always be seen as red, the number 2 as orange, etc. But the more fascinating forms of synesthesia blend sensations from entirely different sensory modalities, like taste and color or music and color: the taste of chicken might elicit a sensation of green, for example, and the timbre of violin a deep purple. THINK IT OVERTHINK IT OVER Take a look at a few of your photos or personal works of art. Can you find examples of linear perspective as a potential depth cue? http://www.flickr.com/photos/glaciernps/4454825783/ http://www.flickr.com/photos/anijdam/2586190200/ http://www.flickr.com/photos/klipsch_fan/230712919/ http://www.flickr.com/photos/scillystuff/1572120541/ http://www.flickr.com/photos/rhondawebber/3699334339/ http://creativecommons.org/licenses/by/2.0 https://www.bbc.co.uk/science/humanbody/body/interactives/senseschallenge/senses.swf GLOSSARYGLOSSARY amplitude:amplitude: height of a wave afterimage:afterimage: continuation of a visual sensation after removal of the stimulus binocular cue:binocular cue: cue that relies on the use of both eyes binocular disparity:binocular disparity: slightly different view of the world that each eye receives blind spot:blind spot: point where we cannot respond to visual information in that portion of the visual field cone:cone: specialized photoreceptor that works best in bright light conditions and detects color cornea:cornea: transparent covering over the eye depth perception:depth perception: ability to perceive depth electromagnetic spectrum:electromagnetic spectrum: all the electromagnetic radiation that occurs in our environment fovea:fovea: small indentation in the retina that contains cones frequency:frequency: number of waves that pass a given point in a given time period hertz (Hz):hertz (Hz): cycles per second; measure of frequency iris:iris: colored portion of the eye lens:lens: curved, transparent structure that provides additional focus for light entering the eye linear perspective:linear perspective: perceive depth in an image when two parallel lines seem to converge monocular cue:monocular cue: cue that requires only one eye opponent-process theory of color perception:opponent-process theory of color perception: color is coded in opponent pairs: black-white, yellow-blue, and red-green optic chiasm:optic chiasm: X-shaped structure that sits just below the brain’s ventral surface; represents the merging of the optic nerves from the two eyes and the separation of information from the two sides of the visual field to the opposite side of the brain optic nerve:optic nerve: carries visual information from the retina to the brain peak:peak: (also, crest) highest point of a wave photoreceptor:photoreceptor: light-detecting cell pupil:pupil: small opening in the eye through which light passes retina:retina: light-sensitive lining of the eye rod:rod: specialized photoreceptor that works well in low light conditions synesthesiasynesthesia: the blending of two or more sensory experiences, or the automatic activation of a secondary (indirect) sensory experience due to certain aspects of the primary (direct) sensory stimulation trichromatic theory of color perception:trichromatic theory of color perception: color vision is mediated by the activity across the three groups of cones trough:trough: lowest point of a wave vestibulo-ocular reflex:vestibulo-ocular reflex: coordination of motion information with visual information that allows you to maintain your gaze on an object while you move visible spectrum:visible spectrum: portion of the electromagnetic spectrum that we can see wavelength:wavelength: length of a wave from one peak to the next peak An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2111 Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Vision. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.52:E-7sLQFP@5/Vision. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/contents/ 4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@5.48 • Modification, adaptation, and original content. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution CC licensed content, Shared previouslyCC licensed content, Shared previously • Waves and Wavelenghts. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.52:1Cicp6CO@8/Waves-and-Wavelengths. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/contents/4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@5.48 • Vision, information and visual and ventral and dorsal pathways, Integration with Other Modalities. Authored byAuthored by: Simona Buetti and Alejandro Lleras . Provided byProvided by: University of Illinois at Urbana-Champaign. Located atLocated at: http://nobaproject.com/modules/vision. ProjectProject: The Noba Project. LicenseLicense: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike • Waves and Wavelengths. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.52:1Cicp6CO@8/Waves-and-Wavelengths. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/contents/4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@5.48 All rights reserved contentAll rights reserved content • Amazing Anamorphic Illusions. Authored byAuthored by: brusspup. Located atLocated at: https://www.youtube.com/watch?v=tBNHPk-Lnkk. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License HEARING What you’ll learn to do: explain the basics of hearing Our auditory system converts pressure waves into meaningful sounds. This translates into our ability to hear the sounds of nature, to appreciate the beauty of music, and to communicate with one another through spoken language. This section will provide an overview of the basic anatomy and function of the auditory system. It will include a discussion of how the sensory stimulus is translated into neural impulses, where in the brain that information is processed, how we perceive pitch, and how we know where sound is coming from. LEARNING OBJECTIVESLEARNING OBJECTIVES • Describe the basic anatomy and function of the auditory system • Show how physical properties of sound waves are associated with perceptual experience • Explain how we encode and perceive pitch and localize sound • Describe types of hearing loss http://cnx.org/contents/Sr8Ev5Og@5.52:E-7sLQFP@5/Vision https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ http://cnx.org/contents/Sr8Ev5Og@5.52:1Cicp6CO@8/Waves-and-Wavelengths https://creativecommons.org/licenses/by/4.0/ http://nobaproject.com/modules/vision https://creativecommons.org/licenses/by-nc-sa/4.0/ http://cnx.org/contents/Sr8Ev5Og@5.52:1Cicp6CO@8/Waves-and-Wavelengths https://creativecommons.org/licenses/by/4.0/ https://www.youtube.com/watch?v=tBNHPk-Lnkk https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/01/27190240/christian-1157044_1280 Figure 1. The ear is divided into outer (pinna and tympanic membrane), middle (the three ossicles: malleus, incus, and stapes), and inner (cochlea and basilar membrane) divisions. How We Hear Our auditory system converts pressure waves into meaningful sounds. This translates into our ability to hear the sounds of nature, to appreciate the beauty of music, and to communicate with one another through spoken language. This section will provide an overview of the basic anatomy and function of the auditory system. It will include a discussion of how the sensory stimulus is translated into neural impulses, where in the brain that information is processed, how we perceive pitch, and how we know where sound is coming from. Anatomy of the Auditory System The ear can be separated into multiple sections. The outer ear includes the pinnapinna, which is the visible part of the ear that protrudes from our heads, the auditory canal, and the tympanic membranetympanic membrane, or eardrum. The middle ear contains three tiny bones known as the ossiclesossicles, which are named the malleusmalleus (or hammer), incusincus (or anvil), and the stapesstapes (or stirrup). The inner ear contains the semi-circular canals, which are involved in balance and movement (the vestibular sense), and the cochlea. The cochleacochlea is a fluid-filled, snail-shaped structure that contains the sensory receptor cells (hair cells) of the auditory system (Figure 1). Sound waves travel along the auditory canal and strike the tympanic membrane, causing it to vibrate. This vibration results in movement of the three ossicles. As the ossicles move, the stapes presses into a thin membrane of the cochlea known as the oval window. As the stapes presses into the oval window, the fluid inside the cochlea begins to move, which in turn stimulates hair cellshair cells, which are auditory receptor cells of the inner ear embedded in the basilar membrane. The basilar membranebasilar membrane is a thin strip of tissue within the cochlea. Sitting on the basilar membrane is the organ of Corti, which runs the entire length of the basilar membrane from the base (by the oval window) to the apex (the “tip” of the spiral). The organ of Corti includes three rows of outer hair cells and one row of inner hair cells. The hair cells sense the vibrations by way of their tiny hairs, or stereocillia. The outer hair cells seem to function to mechanically amplify the sound-induced vibrations, whereas the inner hair cells form synapses with the auditory nerve and transduce those vibrations into action potentials, or neural spikes, which are transmitted along the auditory nerve to higher centers of the auditory pathways. The activation of hair cells is a mechanical process: the stimulation of the hair cell ultimately leads to activation of the cell. As hair cells become activated, they generate neural impulses that travel along the auditory nerve to the brain. Auditory information is shuttled to the inferior colliculus, the medial geniculate nucleus of the thalamus, and finally to the auditory cortex in the temporal lobe of the brain for processing. Like the visual system, there is also evidence suggesting that information about auditory recognition and localization is processed in parallel streams (Rauschecker & Tian, 2000; Renier et al., 2009). An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2113 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2113 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2113 TRY ITTRY IT Watch the process of audition in the following video: Sound Waves As mentioned above, the vibration of the tympanic membrane is what triggers the sequence of events that lead to our perception of sound. Sound waves travel into our ears at various speeds and amplitudes. Like light waves, the physical properties of sound waves are associated with various aspects of our perception of sound. The frequency of a sound wave is associated with our perception of that sound’s pitchpitch. High-frequency sound waves are perceived as high-pitched sounds, while low-frequency sound waves are perceived as low-pitched sounds. The audible range of sound frequencies is between 20 and 20000 Hz, with greatest sensitivity to those frequencies that fall in the middle of this range. As was the case with the visible spectrum, other species show differences in their audible ranges. For instance, chickens have a very limited audible range, from 125 to 2000 Hz. Mice have an audible range from 1000 to 91000 Hz, and the beluga whale’s audible range is from 1000 to 123000 Hz. Our pet dogs and cats have audible ranges of about 70–45000 Hz and 45–64000 Hz, respectively (Strain, 2003). The loudness of a given sound is closely associated with the amplitude of the sound wave. Higher amplitudes are associated with louder sounds. Loudness is measured in terms of decibels (dB)decibels (dB), a logarithmic unit of sound intensity. A typical conversation would correlate with 60 dB; a rock concert might check in at 120 dB (Figure 2). A whisper 5 feet away or rustling leaves are at the low end of our hearing range; sounds like a window air conditioner, a normal conversation, and even heavy traffic or a vacuum cleaner are within a tolerable range. However, there is the potential for hearing damage from about 80 dB to 130 dB: These are sounds of a food processor, power lawnmower, heavy truck (25 feet away), subway train (20 feet away), live rock music, and a jackhammer. The threshold for pain is about 130 dB, a jet plane taking off or a revolver firing at close range (Dunkle, 1982). Figure 2. This figure illustrates the loudness of common sounds. (credit “planes”: modification of work by Max Pfandl; credit “crowd”: modification of work by Christian Holmér; credit “blender”: modification of work by Jo Brodie; credit “car”: modification of work by NRMA New Cars/Flickr; credit “talking”: modification of work by Joi Ito; credit “leaves”: modification of work by Aurelijus Valeiša) LINK TO LEARNINGLINK TO LEARNING Watch this brief video demonstrating how frequency and amplitude interact in our perception of loudness. TRY ITTRY IT Although wave amplitude is generally associated with loudness, there is some interaction between frequency and amplitude in our perception of loudness within the audible range. For example, a 10 Hz sound wave is inaudible no matter the amplitude of the wave. A 1000 Hz sound wave, on the other hand, would vary dramatically in terms of perceived loudness as the amplitude of the wave increased. Of course, different musical instruments can play the same musical note at the same level of loudness, yet they still sound quite different. This is known as the timbre of a sound. TimbreTimbre refers to a sound’s purity, and it is affected by the complex interplay of frequency, amplitude, and timing of sound waves. https://www.lynda.com/Logic-Pro-tutorials/perception-frequency-amplitude/86649/96460-4.html An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2113 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2113 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2113 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2113 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2113 Pitch Perception We know that different frequencies of sound waves are associated with differences in our perception of the pitch of those sounds. Low-frequency sounds are lower pitched, and high-frequency sounds are higher pitched. But how does the auditory system differentiate among various pitches? Several theories have been proposed to account for pitch perception. We’ll discuss two of them here: temporal theory and place theory.The temporaltemporal theorytheory of pitch perception asserts that frequency is coded by the activity level of a sensory neuron. This would mean that a given hair cell would fire action potentials related to the frequency of the sound wave. While this is a very intuitive explanation, we detect such a broad range of frequencies (20–20,000 Hz) that the frequency of action potentials fired by hair cells cannot account for the entire range. Because of properties related to sodium channels on the neuronal membrane that are involved in action potentials, there is a point at which a cell cannot fire any faster (Shamma, 2001).The place theoryplace theory of pitch perception suggests that different portions of the basilar membrane are sensitive to sounds of different frequencies. More specifically, the base of the basilar membrane responds best to high frequencies and the tip of the basilar membrane responds best to low frequencies. Therefore, hair cells that are in the base portion would be labeled as high-pitch receptors, while those in the tip of basilar membrane would be labeled as low-pitch receptors (Shamma, 2001).In reality, both theories explain different aspects of pitch perception. At frequencies up to about 4000 Hz, it is clear that both the rate of action potentials and place contribute to our perception of pitch. However, much higher frequency sounds can only be encoded using place cues (Shamma, 2001). Sound Localization The ability to locate sound in our environments is an important part of hearinghearing. Localizing sound could be considered similar to the way that we perceive depth in our visual fields. Like the monocular and binocular cues that provided information about depth, the auditory system uses both monauralmonaural (one-eared) and binauralbinaural (two- eared) cues to localize sound. Each pinna interacts with incoming sound waves differently, depending on the sound’s source relative to our bodies. This interaction provides a monaural cue that is helpful in locating sounds that occur above or below and in front or behind us. The sound waves received by your two ears from sounds that come from directly above, below, in front, or behind you would be identical; therefore, monaural cues are essential (Grothe, Pecka, & McAlpine, 2010). Figure 3. Localizing sound involves the use of both monaural and binaural cues. (credit “plane”: modification of work by Max Pfandl) An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2113 TRY ITTRY IT Binaural cues, on the other hand, provide information on the location of a sound along a horizontal axis by relying on differences in patterns of vibration of the eardrum between our two ears. If a sound comes from an off-center location, it creates two types of binaural cues: interaural level differences and interaural timing differences. Interaural level differenceInteraural level difference refers to the fact that a sound coming from the right side of your body is more intense at your right ear than at your left ear because of the attenuation of the sound wave as it passes through your head. Interaural timing differenceInteraural timing difference refers to the small difference in the time at which a given sound wave arrives at each ear (Figure 3). Certain brain areas monitor these differences to construct where along a horizontal axis a sound originates (Grothe et al., 2010). An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2113 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2113 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2113 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2113 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2113 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2113 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2113 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2113 Hearing Loss DeafnessDeafness is the partial or complete inability to hear. Some people are born deaf, which is known as congenitalcongenital deafnessdeafness. Many others begin to suffer from conductive hearing lossconductive hearing loss because of age, genetic predisposition, or environmental effects, including exposure to extreme noise (noise-induced hearing loss, as shown in Figure 4, certain illnesses (such as measles or mumps), or damage due to toxins (such as those found in certain solvents and metals). Conductive hearing loss involves structural damage to the ear such as failure in the vibration of the eardrum and/or movement of the ossicles. Figure 4. Environmental factors that can lead to conductive hearing loss include regular exposure to loud music or construction equipment. (a) Rock musicians and (b) construction workers are at risk for this type of hearing loss. (credit a: modification of work by Kenny Sun; credit b: modification of work by Nick Allen) WHAT DO YOU THINK?: DEAF CULTUREWHAT DO YOU THINK?: DEAF CULTURE In the United States and other places around the world, deaf people have their own language, schools, and customs. This is called deaf culture. In the United States, deaf individuals often communicate using American Sign Language (ASL); ASL has no verbal component and is based entirely on visual signs and gestures. The primary mode of communication is signing. One of the values of deaf culture is to continue traditions like using sign language rather than teaching deaf children to try to speak, read lips, or have cochlear implant surgery. When a child is diagnosed as deaf, parents have difficult decisions to make. Should the child be enrolled in mainstream schools and taught to verbalize and read lips? Or should the child be sent to a school for deaf children to learn ASL and have significant exposure to deaf culture? Do you think there might be differences in the way that parents approach these decisions depending on whether or not they are also deaf? Given the mechanical nature by which the sound wave stimulus is transmitted from the eardrum through the ossicles to the oval window of the cochlea, some degree of hearing loss is inevitable. With conductive hearing loss, hearing problems are associated with a failure in the vibration of the eardrum and/or movement of the ossicles. These problems are often dealt with through devices like hearing aids that amplify incoming sound waves to make vibration of the eardrum and movement of the ossicles more likely to occur. When the hearing problem is associated with a failure to transmit neural signals from the cochlea to the brain, it is called sensorineural hearing losssensorineural hearing loss. This type of loss accelerates with age and can be caused by prolonged exposure to loud noises, which causes damage to the hair cells within the cochlea. One disease that results in sensorineural hearing loss is Ménière’s diseaseMénière’s disease. Although not well understood, Ménière’s disease results in a degeneration of inner ear structures that can lead to hearing loss, tinnitus (constant ringing or buzzing), vertigovertigo (a sense of spinning), and an increase in pressure within the inner ear (Semaan & Megerian, 2011). This kind of loss cannot be treated with hearing aids, but some individuals might be candidates for a cochlear implant as a treatment option. Cochlear implantsCochlear implants are electronic devices that consist of a microphone, a speech processor, and an electrode array. The device receives incoming sound information and directly stimulates the auditory nerve to transmit information to the brain. An interactive or media element has been excluded from this version of the text. 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You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2113 TRY ITTRY IT GLOSSARYGLOSSARY basilar membrane:basilar membrane: thin strip of tissue within the cochlea that contains the hair cells which serve as the sensory receptors for the auditory system binaural cue:binaural cue: two-eared cue to localize sound cochlear implant:cochlear implant: electronic device that consists of a microphone, a speech processor, and an electrode array to directly stimulate the auditory nerve to transmit information to the brain conductive hearing loss:conductive hearing loss: failure in the vibration of the eardrum and/or movement of the ossicles congenital deafness:congenital deafness: deafness from birth deafness:deafness: partial or complete inability to hear hair cell:hair cell: auditory receptor cell of the inner ear incus:incus: middle ear ossicle; also known as the anvil interaural: level differenceinteraural: level difference sound coming from one side of the body is more intense at the closest ear because of the attenuation of the sound wave as it passes through the head interaural timing difference:interaural timing difference: small difference in the time at which a given sound wave arrives at each ear malleus:malleus: middle ear ossicle; also known as the hammer Ménière’s disease:Ménière’s disease: results in a degeneration of inner ear structures that can lead to hearing loss, tinnitus, vertigo, and an increase in pressure within the inner ear monaural cue:monaural cue: one-eared cue to localize sound pinna:pinna: visible part of the ear that protrudes from the head THINK IT OVERTHINK IT OVER If you had to choose to lose either your vision or your hearing, which would you choose and why? place theory of pitch perception:place theory of pitch perception: different portions of the basilar membrane are sensitive to sounds of different frequencies sensorineural hearing loss:sensorineural hearing loss: failure to transmit neural signals from the cochlea to the brain stapes:stapes: middle ear ossicle; also known as the stirrup temporal theory of pitch perception:temporal theory of pitch perception: sound’s frequency is coded by the activity level of a sensory neuron tympanic membrane:tympanic membrane: eardrum vertigo:vertigo: spinning sensation An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2113 Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Modification, adaptation, and original content. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike CC licensed content, Shared previouslyCC licensed content, Shared previously • Hearing. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.52:0nKfpXqb@6/Hearing. LicenseLicense: CC BY: Attribution • Information on corti. Authored byAuthored by: Andrew J. Oxenham . Provided byProvided by: University of Minnesota. Located atLocated at: http://nobaproject.com/modules/hearing. ProjectProject: The Noba Project. LicenseLicense: CC BY-NC-SA: Attribution- NonCommercial-ShareAlike All rights reserved contentAll rights reserved content • Process of Hearing. Authored byAuthored by: psy1113. Located atLocated at: https://www.youtube.com/watch?v=pCCcFDoyBxM. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License Public domain contentPublic domain content • Rock concert. Authored byAuthored by: 12matamoros. Provided byProvided by: Pixabay. Located atLocated at: https://pixabay.com/p-1157044/?no_redirect. LicenseLicense: Public Domain: No Known Copyright https://creativecommons.org/licenses/by-nc-sa/4.0/ http://cnx.org/contents/Sr8Ev5Og@5.52:0nKfpXqb@6/Hearing https://creativecommons.org/licenses/by/4.0/ http://nobaproject.com/modules/hearing https://creativecommons.org/licenses/by-nc-sa/4.0/ https://creativecommons.org/licenses/by-nc-sa/4.0/ https://www.youtube.com/watch?v=pCCcFDoyBxM https://pixabay.com/p-1157044/?no_redirect https://creativecommons.org/about/pdm TASTE AND SMELL What you’ll learn to do: describe the basic anatomy and functions of taste, smell, touch, pain, and the vestibular sense Vision and hearing have received an incredible amount of attention from researchers over the years. While there is still much to be learned about how these sensory systems work, we have a much better understanding of them than of our other sensory modalities. In this section, we will explore our chemical senses (taste and smell) and our body senses (touch, temperature, pain, balance, and body position). LEARNING OBJECTIVESLEARNING OBJECTIVES • Summarize the chemical process of taste and smell • Explain the receptors that respond to touch The Chemical Senses Taste (gustation) and smell (olfaction) are called chemical senses because both have sensory receptors that respond to molecules in the food we eat or in the air we breathe. There is a pronounced interaction between our chemical senses. For example, when we describe the flavor of a given food, we are really referring to both gustatory and olfactory properties of the food working in combination. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/01/31152803/3027430438_02821f919d_z Figure 1. (a) Taste buds are composed of a number of individual taste receptors cells that transmit information to nerves. (b) This micrograph shows a close-up view of the tongue’s surface. (credit a: modification of work by Jonas Töle; credit b: scale-bar data from Matt Russell) Taste (Gustation) You have learned since elementary school that there are four basic groupings of tastetaste: sweet, salty, sour, and bitter. Research demonstrates, however, that we have at least six taste groupings. UmamiUmami is our fifth taste. Umami is actually a Japanese word that roughly translates to yummy, and it is associated with a taste for monosodium glutamate (Kinnamon & Vandenbeuch, 2009). There is also a growing body of experimental evidence suggesting that we possess a taste for the fatty content of a given food (Mizushige, Inoue, & Fushiki, 2007). Molecules from the food and beverages we consume dissolve in our saliva and interact with taste receptors on our tongue and in our mouth and throat. Taste budsTaste buds are formed by groupings of taste receptor cells with hair-like extensions that protrude into the central pore of the taste bud (Figure 1). Taste buds have a life cycle of ten days to two weeks, so even destroying some by burning your tongue won’t have any long-term effect; they just grow right back. Taste molecules bind to receptors on this extension and cause chemical changes within the sensory cell that result in neural impulses being transmitted to the brain via different nerves, depending on where the receptor is located. Taste information is transmitted to the medulla, thalamus, and limbic system, and to the gustatory cortex, which is tucked underneath the overlap between the frontal and temporal lobes (Maffei, Haley, & Fontanini, 2012; Roper, 2013). Smell (Olfaction) Olfactory receptorOlfactory receptor cells are located in a mucous membrane at the top of the nose. Small hair-like extensions from these receptors serve as the sites for odor molecules dissolved in the mucus to interact with chemical receptors located on these extensions (Figure 2). Once an odor molecule has bound a given receptor, chemical changes within the cell result in signals being sent to the olfactory bulbolfactory bulb: a bulb-like structure at the tip of the frontal lobe where the olfactory nerves begin. From the olfactory bulb, information is sent to regions of the limbic system and to the primary olfactory cortex, which is located very near the gustatory cortex (Lodovichi & Belluscio, 2012; Spors et al., 2013). Figure 2. Olfactory receptors are the hair-like parts that extend from the olfactory bulb into the mucous membrane of the nasal cavity. Olfactory receptors are complex proteins called G protein-coupled receptors (GPCRs). These structures are proteins that weave back and forth across the membranes of olfactory cells seven times, forming structures outside the cell that sense odorant molecules and structures inside the cell that activate the neural message ultimately conveyed to the brain by olfactory neurons. The structures that sense odorants can be thought of as tiny binding pockets with sites that respond to active parts of molecules (e.g., carbon chains). There are about 350 functional olfactory genes in humans; each gene expresses a particular kind of olfactory receptor. All olfactory receptors of a given kind project to structures called glomeruli (paired clusters of cells found on both sides of the brain). For a single molecule, the pattern of activation across the glomeruli paints a picture of the chemical structure of the molecule. Thus, the olfactory system can identify a vast array of chemicals present in the environment. Most of the odors we encounter are actually mixtures of chemicals (e.g., bacon odor). The olfactory system creates an image for the mixture and stores it in memory just as it does for the odor of a single molecule (Shepherd, 2005). There is tremendous variation in the sensitivity of the olfactory systems of different species. We often think of dogs as having far superior olfactory systems than our own, and indeed, dogs can do some remarkable things with their noses. There is some evidence to suggest that dogs can “smell” dangerous drops in blood glucose levels as well as cancerous tumors (Wells, 2010). Dogs’ extraordinary olfactory abilities may be due to the increased number of functional genes for olfactory receptors (between 800 and 1200), compared to the fewer than 400 observed in humans and other primates (Niimura & Nei, 2007). Many species respond to chemical messages, known as pheromonespheromones, sent by another individual (Wysocki & Preti, 2004). Pheromonal communication often involves providing information about the reproductive status of a potential mate. So, for example, when a female rat is ready to mate, she secretes pheromonal signals that draw attention from nearby male rats. Pheromonal activation is actually an important component in eliciting sexual behavior in the male rat (Furlow, 1996, 2012; Purvis & Haynes, 1972; Sachs, 1997). There has also been a good deal of research (and controversy) about pheromones in humans (Comfort, 1971; Russell, 1976; Wolfgang- Kimball, 1992; Weller, 1998). An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2158 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2158 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2158 TRY ITTRY IT GLOSSARYGLOSSARY olfactory bulb:olfactory bulb: bulb-like structure at the tip of the frontal lobe, where the olfactory nerves begin olfactory receptor:olfactory receptor: sensory cell for the olfactory system pheromone:pheromone: chemical message sent by another individual taste bud:taste bud: grouping of taste receptor cells with hair-like extensions that protrude into the central pore of the taste bud umami:umami: taste for monosodium glutamate LEARNING OBJECTIVESLEARNING OBJECTIVES As mentioned earlier, a food’s flavor represents an interaction of both gustatory and olfactory information. Think about the last time you were seriously congested due to a cold or the flu. What changes did you notice in the flavors of the foods that you ate during this time? Licensing & AttributionsLicensing & Attributions CC licensed content, Shared previouslyCC licensed content, Shared previously • The Other Senses. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.49:Nw9FOKLs@6/The-Other-Senses. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/ contents/4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@5.48 • Paragraph on olfactory receptors. Authored byAuthored by: Linda Bartoshuk and Derek Snyder . Provided byProvided by: University of Florida. Located atLocated at: http://nobaproject.com/modules/taste-and-smell?r=LDIzOTky. ProjectProject: The Noba Project. LicenseLicense: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike • Touch photo. Authored byAuthored by: Wendy Longo. Located atLocated at: https://www.google.com/search?q=5+senses&rlz=1C5CHFA_enUS727US727&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjCwNPv1-zRAhUJj1QKHdLfC- EQ_AUICCgB&biw=1255&bih=743#tbs=sur:fc&tbm=isch&q=touch&imgrc=D65TnqDgRi27_M%3A. LicenseLicense: CC BY-ND: Attribution-NoDerivatives TOUCH AND PAIN LEARNING OBJECTIVESLEARNING OBJECTIVES • Explain the receptors that respond to touch http://cnx.org/contents/Sr8Ev5Og@5.49:Nw9FOKLs@6/The-Other-Senses https://creativecommons.org/licenses/by/4.0/ http://nobaproject.com/modules/taste-and-smell?r=LDIzOTky https://creativecommons.org/licenses/by-nc-sa/4.0/ https://www.google.com/search?q=5+senses&rlz=1C5CHFA_enUS727US727&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjCwNPv1-zRAhUJj1QKHdLfC-EQ_AUICCgB&biw=1255&bih=743#tbs=sur:fc&tbm=isch&q=touch&imgrc=D65TnqDgRi27_M%3A https://www.google.com/search?q=5+senses&rlz=1C5CHFA_enUS727US727&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjCwNPv1-zRAhUJj1QKHdLfC-EQ_AUICCgB&biw=1255&bih=743#tbs=sur:fc&tbm=isch&q=touch&imgrc=D65TnqDgRi27_M%3A https://creativecommons.org/licenses/by-nd/4.0/ Figure 1. There are many types of sensory receptors located in the skin, each attuned to specific touch-related stimuli. • Explain the importance of pain and give examples of how expectations and context affect pain and touch experiences. Touch, Thermoception, and Noiception A number of receptors are distributed throughout the skin to respond to various touch-related stimuli (Figure 1). These receptors include Meissner’s corpuscles, Pacinian corpuscles, Merkel’s disks, and Ruffini corpuscles. Meissner’s corpusclesMeissner’s corpuscles respond to pressure and lower frequency vibrations, and Pacinian corpusclePacinian corpuscles detect transient pressure and higher frequency vibrations. Merkel’s disksMerkel’s disks respond to light pressure, while RuffiniRuffini corpusclescorpuscles detect stretch (Abraira & Ginty, 2013). The skin can convey many sensations, such as the biting cold of a wind, the comfortable pressure of a hand holding yours, or the irritating itch from a woolen scarf. The different types of information activate specific receptors that convert the stimulation of the skin to electrical nerve impulses, a process called transduction. There are three main groups of receptors in our skin: mechanoreceptors, responding to mechanical stimuli, such as stroking, stretching, or vibration of the skin; thermoreceptors, responding to cold or hot temperatures; and chemoreceptors, responding to certain types of chemicals either applied externally or released within the skin (such as histamine from an inflammation). For an overview of the different receptor types and their properties, see Table 1. The experience of pain usually starts with activation of nociceptorsnociceptors—receptors that fire specifically to potentially tissue-damaging stimuli. Most of the nociceptors are subtypes of either chemoreceptors or mechanoreceptors. When tissue is damaged or inflamed, certain chemical substances are released from the cells, and these substances activate the chemosensitive nociceptors. Mechanoreceptive nociceptors have a high threshold for activation—they respond to mechanical stimulation that is so intense it might damage the tissue. Sensory information collected from the receptors and free nerve endings travels up the spinal cord and is transmitted to regions of the medulla, thalamus, and ultimately to somatosensory cortex, which is located in the postcentral gyrus of the parietal lobe. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2160 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2160 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2160 TRY ITTRY IT Table 1. Categories of low-threshold mechanoreceptors* Identity of receptorIdentity of receptor Size of receptor*Size of receptor* Type of skin whereType of skin where foundfound Speed ofSpeed of adaptation*adaptation* AdequateAdequate stimulus*stimulus* Merkel’s disks small, sharp borders glabrous* slow pressure Meissner’s corpusles small, sharp borders glabrous rapid indentation Ruffini corpuscles large, diffuse borders hairy + glabrous slow stretching Pacinian corpuscles large, diffuse borders hairy + glabrous rapid vibration *Terms: Adequate stimulusAdequate stimulus-the type of stimulus that the receptor is specialized to receive and respond to. Glabrous skinGlabrous skin-the hairless skin found on our palms and the soles of our feet. This skin has a higher density of receptors of a more complex range, which reflects the fact that we use these areas of our body to actively explore our surroundings and to discriminate tactile properties of objects we’re interacting with. Low-threshold mechanoreceptors-Low-threshold mechanoreceptors-mechanoreceptors that respond to stimulus that is so light it doesn’t threaten to damage the tissue around it. high-threshold mechanoreceptors respond to stimulation of higher intensity, and are a type of nociceptor. Receptive fieldReceptive field-the space of skin or tissue in which stimulation will elicit a response in the receptor. Smaller receptive fields make the receptor more sensitive to details. Speed adaptationSpeed adaptation-slowly adapting mechanoreceptors continue to fire action potentials during sustained stimulation. Rapidly adapting mechanoreceptors continue to fire action potentials in response to stimulus onset and offset (i.e. to stimuli changes), and help detect stimulus movement on the skin. LIFE WITHOUT PAIN?LIFE WITHOUT PAIN? Imagine a life free of pain. How would it be—calm, fearless, serene? Would you feel invulnerable, invincible? Getting rid of pain is a popular quest—a quick search for “pain-free life” on Google returns well over 4 million hits—including links to various bestselling self-help guides promising a pain-free life in only 7 steps, 6 weeks, or 3 minutes. Pain management is a billion-dollar market, and involves much more than just pharmaceuticals. Surely a life with no pain would be a better one? Well, consider one of the “lucky few”: 12-year-old “Thomas” has never felt deep pain. Not even when a fracture made him walk around with one leg shorter than the other, so that the bones of his healthy leg were slowly crushed to destruction underneath the knee joint. For Thomas and other members of a large Swedish family, life without pain is a harsh reality because of a mutated gene that affects the growth of the nerves conducting deep pain. Most of those affected suffer from joint damage and frequent fractures to bones in their feet and hands; some end up in wheelchairs even before they reach puberty (Minde et al., 2004). It turns out pain—generally—serves us well. Living without a sense of touch sounds less attractive than being free of pain—touch is a source of pleasure and essential to how we feel. Losing the sense of touch has severe implications—something patient G. L. experienced when an antibiotics treatment damaged the type of nerves that signal touch from her skin and the position of her joints and muscles. She reported feeling like she’d lost her physical self from her nose down, making her “disembodied”—like she no longer had any connection to the body attached to her head. If she didn’t look at her arms and legs they could just “wander off” without her knowing—initially she was unable to walk, and even after she relearned this skill she was so dependent on her visual attention that closing her eyes would cause her to land in a hopeless heap on the floor. Only light caresses like those from her children’s hands can make her feel she has a body, but even these sensations remain vague and elusive (Olausson et al., 2002; Sacks, 1985). LINK TO LEARNINGLINK TO LEARNING Watch this video to learn more about congenital insensitivity to pain. Pain Perception Pain is an unpleasant experience that involves both physical and psychological components. Feeling pain is quite adaptive because it makes us aware of an injury, and it motivates us to remove ourselves from the cause of that injury. In addition, pain also makes us less likely to suffer additional injury because we will be gentler with our injured body parts. Generally speaking, pain can be considered to be neuropathic or inflammatory in nature. Pain that signals some type of tissue damage is known as inflammatory paininflammatory pain. In some situations, pain results from damage to neurons of either the peripheral or central nervous system. As a result, pain signals that are sent to the brain get exaggerated. This type of pain is known as neuropathic painneuropathic pain. Multiple treatment options for pain relief range from relaxation therapy to the use of analgesic medications to deep brain stimulation. The most effective treatment option for a given individual will depend on a number of considerations, including the severity and persistence of the pain and any medical/psychological conditions. Some individuals are born without the ability to feel pain. This very rare genetic disorder is known as congenitalcongenital insensitivity to paininsensitivity to pain (or congenital analgesiacongenital analgesia). While those with congenital analgesia can detect differences in temperature and pressure, they cannot experience pain. As a result, they often suffer significant injuries. Young children have serious mouth and tongue injuries because they have bitten themselves repeatedly. Not surprisingly, individuals suffering from this disorder have much shorter life expectancies due to their injuries and secondary infections of injured sites (U.S. National Library of Medicine, 2013). https://www.youtube.com/watch?v=1vLsZ_dXFAg Action Potentials in the Receptor Cells Travel as Nerve Impulses with Different Speeds When you step on a pin, this activates a host of mechanoreceptors, many of which are nociceptors. You may have noticed that the sensation changes over time. First you feel a sharp stab that propels you to remove your foot, and only then you feel a wave of more aching pain. The sharp stab is signaled via fast-conducting A-fibers, which project to the somatosensory cortex. This part of the cortex is somatotopically organized—that is, the sensory signals are represented according to where in the body they stem from (see homunculus illustration, Figure 2). The unpleasant ache you feel after the sharp pin stab is a separate, simultaneous signal sent from the nociceptors in your foot via thin C-pain or Aδ-fibers to the insular cortex and other brain regions involved in processing of emotion and interoception (see Figure 3a for a schematic representation of this pathway). The experience of stepping on a pin is, in other words, composed by two separate signals: one discriminatory signal allowing us to localize the touch stimulus and distinguish whether it’s a blunt or a sharp stab; and one affective signal that lets us know that stepping on the pin is bad. It is common to divide pain into sensory–discriminatory and affective–motivational aspects (Auvray, Myin, & Spence, 2010). This distinction corresponds, at least partly, to how this information travels from the peripheral to the central nervous system and how it is processed in the brain (Price, 2000). Figure 2a. The Homunculus: Homunculus means “little man”, and here you see a scale model of the human body distorted to reflect the relative space that body parts occupy in the somatosensory cortex. As you can see, the lips, hands, feet and genitals send more somatosensory projections to the brain than do any other body parts. Figure 2b. Cortical mapping of the sensory homunculus: The body parts are represented in specific locations on the somatosensory cortex. Representations map out somatotopically, with the feet located medially and shoulders and arms laterally to the interhemispheric fissure. Facial structures are represented in a different location to the scalp and head; the face oriented «upside down» with the forehead pointing towards the shoulders. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/10/27135056/homunculus https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/10/27135056/homunculus Figure 3: Pain processing pathways. Left – Ascending pain pathways: An injury is signaled simultaneously via fast-conducting Aα or Aβ-fibres and slow-conducting C-pain or Aδ-fibres. The fast A-fibres signal pressure, stretching and other tissue movements to the somatosensory cortex via the dorsal column nuclei. The C-pain and Aδ-fibres sends pain information from nociceptors in the tissue or skin, and transmits these signals to second order neurons in the dorsal horn of the spinal cord. The second order Pain Is Necessary for Survival, but Our Brain Can Stop It if It Needs To In April 2003, the climber Aron Ralston found himself at the floor of Blue John Canyon in Utah, forced to make an appalling choice: face a slow but certain death—or amputate his right arm. Five days earlier he fell down the canyon—since then he had been stuck with his right arm trapped between an 800-lb boulder and the steep sandstone wall. Weak from lack of food and water and close to giving up, it occurred to him like an epiphany that if he broke the two bones in his forearm he could manage to cut off the rest with his pocket knife. The thought of freeing himself and surviving made him so exited he spent the next 40 minutes completely engrossed in the task: first snapping his bones using his body as a lever, then sticking his fingers into the arm, pinching bundles of muscle fibers and severing them one by one, before cutting the blue arteries and the pale “noodle-like” nerves. The pain was unimportant. Only cutting through the thick white main nerve made him stop for a minute—the flood of pain, he describes, was like thrusting his entire arm “into a cauldron of magma.” Finally free, he rappelled down a cliff and walked another 7 miles until he was rescued by some hikers (Ralston, 2010). How is it possible to do something so excruciatingly painful to yourself, as Aron Ralston did, and still manage to walk, talk, and think rationally afterwards? The answer lies within the brain, where signals from the body are interpreted. When we perceive somatosensory and nociceptive signals from the body, the experience is highly subjective and malleable by motivation, attention, emotion, and context. neurons then cross over to the opposite side, where they form the ascending spinothalamic tract. This tract projects signals to nuclei in the medulla and midbrain on the way up to the thalamus (T). The thalamus relays the information to the somatosensory and insular cortex, as well as cortical regions mediating different aspects of the pain experience such as affective responses in the cingulate cortex. Right – Descending pain modulation pathways: Information from the environment and certain motivational states can activate this top–down pathway. Several areas in the limbic forebrain including the anterior cingulate and insular cortex, nuclei in the amygdala and the hypothalamus (H), project to the midbrain periaqueductal grey (PAG), which then modulates ascending pain transmission from the afferent pain system indirectly through the rostral ventromedial medulla (RVM) in the brainstem. This modulating system produces analgesia by the release of endogenous opioids, and uses ON- and OFF-cells to exert either inhibitory (green) or facilitatory (red) control of nociceptive signals at the spinal dorsal horn. The Motivation–Decision Model and Descending Modulation of Pain According to the motivation–decision model, the brain automatically and continuously evaluates the pros and cons of any situation—weighing impending threats and available rewards (Fields, 2004, 2006). Anything more important for survival than avoiding the pain activates the brain’s descending pain modulatory system—a top- down system involving several parts of the brain and brainstem, which inhibits nociceptive signaling so that the more important actions can be attended to. In Aron’s extreme case, his actions were likely based on such an unconscious decision process—taking into account his homeostatic state (his hunger, thirst, the inflammation and decay of his crushed hand slowly affecting the rest of his body), the sensory input available (the sweet smell of his dissolving skin, the silence around him indicating his solitude), and his knowledge about the threats facing him (death, or excruciating pain that won’t kill him) versus the potential rewards (survival, seeing his family again). Aron’s story illustrates the evolutionary advantage to being able to shut off pain: The descending pain modulatory system allows us to go through with potentially life-saving actions. However, when one has reached safety or obtained the reward, healing is more important. The very same descending system can then “crank up” nociception from the body to promote healing and motivate us to avoid potentially painful actions. To facilitate or inhibit nociceptive signals from the body, the descending pain modulatory system uses a set of ON- or OFF-cells in the brainstem, which regulates how much of the nociceptive signal reaches the brain. The descending system is dependent on opioid signaling, and analgesics like morphine relieve pain via this circuit (Petrovic, Kalso, Petersson, & Ingvar, 2002). The Analgesic Power of Reward Thinking about the good things, like his loved ones and the life ahead of him, was probably pivotal to Aron’s survival. The promise of a reward can be enough to relieve pain. Expecting pain relief (getting less pain is often the best possible outcome if you’re in pain, i.e., it is a reward) from a medical treatment contributes to the placebo effect—where pain relief is due at least partly to your brain’s descending modulation circuit, and such relief depends on the brain’s own opioid system (Eippert et al., 2009; Eippert, Finsterbusch, Bingel, & Buchel, 2009; Levine, Gordon, & Fields, 1978). Eating tasty food, listening to good music, or feeling pleasant touch on your skin also decreases pain in both animals and humans, presumably through the same mechanism in the brain (Leknes & Tracey, 2008). In a now classic experiment, Dum and Herz (1984) either fed rats normal rat food or let them feast on highly rewarding chocolate-covered candy (rats love sweets) while standing on a metal plate until they learned exactly what to expect when placed there. When the plate was heated up to a noxious/painful level, the rats that expected candy endured the temperature for twice as long as the rats expecting normal chow. Moreover, this effect was completely abolished when the rats’ opioid (endorphin) system was blocked with a drug, indicating that the analgesic effect of reward anticipation was caused by endorphin release. For Aron the climber, both the stress from knowing that death was impending and the anticipation of the reward it would be to survive probably flooded his brain with endorphins, contributing to the wave of excitement and euphoria he experienced while he carried out the amputation “like a five-year-old unleashed on his Christmas presents” (Ralston, 2010). This altered his experience of the pain from the extreme tissue damage he was causing and enabled him to focus on freeing himself. Our brain, it turns out, can modulate the perception of how An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2160 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2160 TRY ITTRY IT unpleasant pain is, while still retaining the ability to experience the intensity of the sensation (Rainville, Duncan, Price, Carrier, & Bushnell, 1997; Rainville, Feine, Bushnell, & Duncan, 1992). Social rewards, like holding the hand of your boyfriend or girlfriend, have pain-reducing effects. Even looking at a picture of him/her can have similar effects—in fact, seeing a picture of a person we feel close to not only reduces subjective pain ratings, but also the activity in pain-related brain areas (Eisenberger et al., 2011). The most common things to do when wanting to help someone through a painful experience—being present and holding the person’s hand—thus seems to have a measurably positive effect. The Power of the Mind The context of pain and touch has a great impact on how we interpret it. Just imagine how different it would feel to Aron if someone amputated his hand against his will and for no discernible reason. Prolonged pain from injuries can be easier to bear if the incident causing them provides a positive context—like a war wound that testifies to a soldier’s courage and commitment—or phantom pain from a hand that was cut off to enable life to carry on. The relative meaning of pain is illustrated by a recent experiment, where the same moderately painful heat was administered to participants in two different contexts—one control context where the alternative was a non-painful heat; and another where the alternative was an intensely painful heat. In the control context, where the moderate heat was the least preferable outcome, it was (unsurprisingly) rated as painful. In the other context it was the best possible outcome, and here the exact same moderately painful heat was actually rated as pleasant—because it meant the intensely painful heat had been avoided. This somewhat surprising change in perception—where pain becomes pleasant because it represents relief from something worse—highlights the importance of the meaning individuals ascribe to their pain, which can have decisive effects in pain treatment (Leknes et al., 2013). In the case of touch, knowing who or what is stroking your skin can make all the difference—try thinking about slugs the next time someone strokes your skin if you want an illustration of this point. Pain and pleasure not only share modulatory systems—another common attribute is that we don’t need to be on the receiving end of it ourselves in order to experience it. How did you feel when you read about Aron cutting through his own tissue, or “Thomas” destroying his own bones unknowingly? Did you cringe? It’s quite likely that some of your brain areas processing affective aspects of pain were active even though the nociceptors in your skin and deep tissue were not firing. Pain can be experienced vicariously, as can itch, pleasurable touch, and other sensations. Tania Singer and her colleagues found in an fMRI study that some of the same brain areas that were active when participants felt pain on their own skin (anterior cingulate and insula) were also active when they were given a signal that a loved one was feeling the pain. Those who were most “empathetic” also showed the largest brain responses (Singer et al., 2004). A similar effect has been found for pleasurable touch: The posterior insula of participants watching videos of someone else’s arm being gently stroked shows the same activation as if they were receiving the touch themselves (Morrison, Bjornsdotter, & Olausson, 2011). GLOSSARYGLOSSARY congenital insensitivity to pain (congenital analgesia):congenital insensitivity to pain (congenital analgesia): genetic disorder that results in the inability to experience pain inflammatory pain:inflammatory pain: signal that some type of tissue damage has occurred Meissner’s corpuscle:Meissner’s corpuscle: touch receptor that responds to pressure and lower frequency vibrations Merkel’s disk:Merkel’s disk: touch receptor that responds to light touch neuropathic pain:neuropathic pain: pain from damage to neurons of either the peripheral or central nervous system nociception:nociception: sensory signal indicating potential harm and maybe pain Pacinian corpuscle:Pacinian corpuscle: touch receptor that detects transient pressure and higher frequency vibrations Ruffini corpuscle:Ruffini corpuscle: touch receptor that detects stretch vestibular sense:vestibular sense: contributes to our ability to maintain balance and body posture Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Modification and adaptation, addition of Noba Link to Learning and CrashCourse video. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution CC licensed content, Shared previouslyCC licensed content, Shared previously • The Other Senses. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.49:Nw9FOKLs@6/The-Other-Senses. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/ contents/4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@5.48 • Touch and Pain, information on mechanoreceptors through the power of the mind. Authored byAuthored by: Guro E. Loseth, Dan-Mikael Ellingson, and Siri Leknes . Provided byProvided by: University of Oslo, University of Gothenburg. LocatedLocated atat: http://nobaproject.com/modules/touch-and-pain. ProjectProject: The Noba Project. LicenseLicense: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike THE VESTIBULAR SENSE LEARNING OBJECTIVESLEARNING OBJECTIVES • Describe the basic functions of the vestibular, proprioceptive, and kinesthetic sensory systems The Vestibular Sense, Proprioception, and Kinesthesia The vestibular sensevestibular sense contributes to our ability to maintain balance and body posture. As Figure 1 shows, the major sensory organs (utricle, saccule, and the three semicircular canals) of this system are located next to the cochlea in the inner ear. The vestibular organs are fluid-filled and have hair cells, similar to the ones found in the auditory system, which respond to movement of the head and gravitational forces. When these hair cells are stimulated, they send signals to the brain via the vestibular nerve. Although we may not be consciously aware of our vestibular system’s sensory information under normal circumstances, its importance is apparent when we experience motion sickness and/or dizziness related to infections of the inner ear (Khan & Chang, 2013). https://creativecommons.org/licenses/by/4.0/ http://cnx.org/contents/Sr8Ev5Og@5.49:Nw9FOKLs@6/The-Other-Senses https://creativecommons.org/licenses/by/4.0/ http://nobaproject.com/modules/touch-and-pain https://creativecommons.org/licenses/by-nc-sa/4.0/ Figure 1. The major sensory organs of the vestibular system are located next to the cochlea in the inner ear. These include the utricle, saccule, and the three semicircular canals (posterior, superior, and horizontal). In addition to maintaining balance, the vestibular system collects information critical for controlling movement and the reflexes that move various parts of our bodies to compensate for changes in body position. Therefore, both proprioceptionproprioception (perception of body position) and kinesthesiakinesthesia (perception of the body’s movement through space) interact with information provided by the vestibular system. These sensory systems also gather information from receptors that respond to stretch and tension in muscles, joints, skin, and tendons (Lackner & DiZio, 2005; Proske, 2006; Proske & Gandevia, 2012). Proprioceptive and kinesthetic information travels to the brain via the spinal column. Several cortical regions in addition to the cerebellum receive information from and send information to the sensory organs of the proprioceptive and kinesthetic systems. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2170 LINK TO LEARNINGLINK TO LEARNING You can review the things you learned about the senses in the following CrashCourse video: An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2170 TRY ITTRY IT GLOSSARYGLOSSARY kinesthesia:kinesthesia: perception of the body’s movement through space proprioception:proprioception: perception of body position vestibular sense:vestibular sense: contributes to our ability to maintain balance and body posture An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2170 DefinitionDefinition ApplicationApplication Vestibular Sense Sensory system that contributes to balance and the sense of spatial orientation. You have an ear infection and frequently feel dizzy. Or if you were to experience vertigo, you might feel like your entire body was spinning in space and be unable to walk. Propioception The sense of the position of parts of the body, relative to other neighboring parts of the body. Focuses on the body’s cognitive awareness of movement. You step off a curb and know where to put your foot. You push an elevator button and control how hard you have to press down with your fingers. Kinesthesia Awareness of the position and movement of the parts of the body using sensory organs in joints and muscles. Kinesthesia is a key component in muscle memory and hand-eye coordination. It is more behavioral than propioception. You are aware of your arm movement while swinging a golf club. Focuses on the body’s movements and not on equilibrium or balance. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2117 Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Modification, adaptation, and original content. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY-SA: Attribution-ShareAlike CC licensed content, Shared previouslyCC licensed content, Shared previously • The Other Senses. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.49:Nw9FOKLs@6/The-Other-Senses. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/ contents/4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@5.48 • Homunculus - Crash Course Psychology #6. Provided byProvided by: CrashCourse. Located atLocated at: https://www.youtube.com/watch?v=fxZWtc0mYpQ. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License • Additional Sensory Systems, information for chart. Provided byProvided by: Boundless. Located atLocated at: https://www.boundless.com/psychology/textbooks/boundless-psychology-textbook/sensation-and-perception-5/sensory- processes-38/additional-sensory-systems-166-12701/. ProjectProject: Boundless Psychology. LicenseLicense: CC BY-SA: Attribution-ShareAlike PERCEPTION What you’ll learn to do: define perception and give examples of gestalt principles and multimodal perception Seeing something is not the same thing as making sense of what you see. Why is it that our senses are so easily fooled? In this section, you will come to see how our perceptions are not infallible, and they can be influenced by bias, prejudice, and other factors. Psychologists are interested in how these false perceptions influence our thoughts and behavior. Watch this CrashCourse video for a good overview of perception: LEARNING OBJECTIVESLEARNING OBJECTIVES • Give examples of gestalt principles, including the figure-ground relationship, proximity, similarity, continuity, and closure • Define the basic terminology and basic principles of multimodal perception • Give examples of multimodal and crossmodal behavioral effects https://creativecommons.org/licenses/by-sa/4.0/ http://cnx.org/contents/Sr8Ev5Og@5.49:Nw9FOKLs@6/The-Other-Senses https://creativecommons.org/licenses/by/4.0/ https://www.youtube.com/watch?v=fxZWtc0mYpQ https://www.boundless.com/psychology/textbooks/boundless-psychology-textbook/sensation-and-perception-5/sensory-processes-38/additional-sensory-systems-166-12701/ https://www.boundless.com/psychology/textbooks/boundless-psychology-textbook/sensation-and-perception-5/sensory-processes-38/additional-sensory-systems-166-12701/ https://creativecommons.org/licenses/by-sa/4.0/ https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/02/01204244/5704563713_dd5a8c0de1_o Gestalt Principles of Perception In the early part of the 20th century, Max Wertheimer published a paper demonstrating that individuals perceived motion in rapidly flickering static images—an insight that came to him as he used a child’s toy tachistoscope. Wertheimer, and his assistants Wolfgang Köhler and Kurt Koffka, who later became his partners, believed that perception involved more than simply combining sensory stimuli. This belief led to a new movement within the field of psychology known as Gestalt psychologyGestalt psychology. The word gestalt literally means form or pattern, but its use reflects the idea that the whole is different from the sum of its parts. In other words, the brain creates a perception that is more than simply the sum of available sensory inputs, and it does so in predictable ways. Gestalt psychologists translated these predictable ways into principles by which we organize sensory information. As a result, Gestalt psychology has been extremely influential in the area of sensation and perception (Rock & Palmer, 1990). One Gestalt principle is the figure-ground relationshipfigure-ground relationship. According to this principle, we tend to segment our visual world into figure and ground. Figure is the object or person that is the focus of the visual field, while the ground is the background. As Figure 1 shows, our perception can vary tremendously, depending on what is perceived as figure and what is perceived as ground. Presumably, our ability to interpret sensory information depends on what we label as figure and what we label as ground in any particular case, although this assumption has been called into question (Peterson & Gibson, 1994; Vecera & O’Reilly, 1998). Figure 1. The concept of figure-ground relationship explains why this image can be perceived either as a vase or as a pair of faces. Another Gestalt principle for organizing sensory stimuli into meaningful perception is proximityproximity. This principle asserts that things that are close to one another tend to be grouped together, as Figure 2 illustrates. Figure 2. The Gestalt principle of proximity suggests that you see (a) one block of dots on the left side and (b) three columns on the right side. How we read something provides another illustration of the proximity concept. For example, we read this sentence like this, notl iket hiso rt hat. We group the letters of a given word together because there are no spaces between the letters, and we perceive words because there are spaces between each word. Here are some more examples: Cany oum akes enseo ft hiss entence? What doth es e wor dsmea n? We might also use the principle of similaritysimilarity to group things in our visual fields. According to this principle, things that are alike tend to be grouped together (Figure 3). For example, when watching a football game, we tend to group individuals based on the colors of their uniforms. When watching an offensive drive, we can get a sense of the two teams simply by grouping along this dimension. Figure 3. When looking at this array of dots, we likely perceive alternating rows of colors. We are grouping these dots according to the principle of similarity. Two additional Gestalt principles are the law oflaw of continuitycontinuity (or good continuation) and closureclosure. The law of continuity suggests that we are more likely to perceive continuous, smooth flowing lines rather than jagged, broken lines (Figure 4). The principle of closure states that we organize our perceptions into complete objects rather than as a series of parts (Figure 5). Figure 4. Good continuation would suggest that we are more likely to perceive this as two overlapping lines, rather than four lines meeting in the center. Figure 5. Closure suggests that we will perceive a complete circle and rectangle rather than a series of segments. LINK TO LEARNINGLINK TO LEARNING Watch this podcast showing real world illustrations of Gestalt principles. DIG DEEPER: THE DEPTHS OF PERCEPTION: BIAS, PREJUDICE, ANDDIG DEEPER: THE DEPTHS OF PERCEPTION: BIAS, PREJUDICE, AND CULTURAL FACTORSCULTURAL FACTORS In this module, you have learned that perception is a complex process. Built from sensations, but influenced by our own experiences, biases, prejudices, and cultures, perceptions can be very different from person to person. Research suggests that implicit racial prejudice and stereotypes affect perception. For instance, several studies have demonstrated that non-Black participants identify weapons faster and are more likely to identify non- weapons as weapons when the image of the weapon is paired with the image of a Black person (Payne, 2001; Payne, Shimizu, & Jacoby, 2005). Furthermore, White individuals’ decisions to shoot an armed target in a video game is made more quickly when the target is Black (Correll, Park, Judd, & Wittenbrink, 2002; Correll, Urland, & Ito, 2006). This research is important, considering the number of very high-profile cases in the last few decades in which young Blacks were killed by people who claimed to believe that the unarmed individuals were armed and/or represented some threat to their personal safety. TRY ITTRY IT According to Gestalt theorists, pattern perceptionpattern perception, or our ability to discriminate among different figures and shapes, occurs by following the principles described above. You probably feel fairly certain that your perception accurately matches the real world, but this is not always the case. Our perceptions are based on perceptualperceptual hypotheseshypotheses: educated guesses that we make while interpreting sensory information. These hypotheses are informed by a number of factors, including our personalities, experiences, and expectations. We use these hypotheses to generate our perceptual set. For instance, research has demonstrated that those who are given verbal priming produce a biased interpretation of complex ambiguous figures (Goolkasian & Woodbury, 2010). https://secure-hwcdn.libsyn.com/p/e/c/0/ec024ff6bc3adce3/TPF_031Gestalt_020709.m4v?c_id=1316744&expiration=1485984203&hwt=3dfc11440d95d65189642fcece86be5d An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2117 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2117 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2117 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2117 Figure 6. The way we receive the information from the world is called sensation while our interpretation of that information is called perception. [Image: Laurens van Lieshou] THINK IT OVERTHINK IT OVER Have you ever listened to a song on the radio and sung along only to find out later that you have been singing the wrong lyrics? Once you found the correct lyrics, did your perception of the song change? Multi-Modal Perception Although it has been traditional to study the various senses independently, most of the time, perception operates in the context of information supplied by multiple sensorysensory modalitiesmodalities at the same time. For example, imagine if you witnessed a car collision. You could describe the stimulus generated by this event by considering each of the senses independently; that is, as a set of unimodalunimodal stimuli. Your eyes would be stimulated with patterns of light energy bouncing off the cars involved. Your ears would be stimulated with patterns of acoustic energy emanating from the collision. Your nose might even be stimulated by the smell of burning rubber or gasoline. However, all of this information would be relevant to the same thing: your perception of the car collision. Indeed, unless someone was to explicitly ask you to describe your perception in unimodal terms, you would most likely experience the event as a unified bundle of sensations from multiple senses. In other words, your perception would be multimodalmultimodal. The question is whether the various sources of information involved in this multimodal stimulus are processed separately by the perceptual system or not. For the last few decades, perceptual research has pointed to the importance of multimodal perceptionmultimodal perception: the effects on the perception of events and objects in the world that are observed when there is information from more than one sensory modality. Most of this research indicates that, at some point in perceptual processing, information from the various sensory modalities is integratedintegrated. In other words, the information is combined and treated as a unitary representation of the world. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/10/27203138/percep https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/10/27203138/percep Behavioral Effects of Multimodal Perception Although neuroscientists tend to study very simple interactions between neurons, the fact that they’ve found so many crossmodal areas of the cortex seems to hint that the way we experience the world is fundamentally multimodal. Our intuitions about perception are consistent with this; it does not seem as though our perception of events is constrained to the perception of each sensory modality independently. Rather, we perceive a unified world, regardless of the sensory modality through which we perceive it. It will probably require many more years of research before neuroscientists uncover all the details of the neural machinery involved in this unified experience. In the meantime, experimental psychologists have contributed to our understanding of multimodal perception through investigations of the behavioral effects associated with it. These effects fall into two broad classes. The first class—multimodal phenomenamultimodal phenomena—concerns the binding of inputs from multiple sensory modalities and the effects of this binding on perception. The second class—crossmodalcrossmodal phenomenaphenomena—concerns the influence of one sensory modality on the perception of another (Spence, Senkowski, & Roder, 2009). Multimodal Phenomena Audiovisual Speech Multimodal phenomena concern stimuli that generate simultaneous (or nearly simultaneous) information in more than one sensory modality. As discussed above, speech is a classic example of this kind of stimulus. When an individual speaks, she generates sound waves that carry meaningful information. If the perceiver is also looking at the speaker, then that perceiver also has access to visual patterns that carry meaningful information. Of course, as anyone who has ever tried to lipread knows, there are limits on how informative visual speech information is. Even so, the visual speech pattern alone is sufficient for very robust speech perception. Most people assume that deaf individuals are much better at lipreading than individuals with normal hearing. It may come as a surprise to learn, however, that some individuals with normal hearing are also remarkably good at lipreading (sometimes called “speechreading”). In fact, there is a wide range of speechreading ability in both normal hearing and deaf populations (Andersson, Lyxell, Rönnberg, & Spens, 2001). However, the reasons for this wide range of performance are not well understood (Auer & Bernstein, 2007; Bernstein, 2006; Bernstein, Auer, & Tucker, 2001; Mohammed et al., 2005). How does visual information about speech interact with auditory information about speech? One of the earliest investigations of this question examined the accuracy of recognizing spoken words presented in a noisy context, much like in the example above about talking at a crowded party. To study this phenomenon experimentally, some irrelevant noise (“white noise”—which sounds like a radio tuned between stations) was presented to participants. Embedded in the white noise were spoken words, and the participants’ task was to identify the words. There were two conditions: one in which only the auditory component of the words was presented (the “auditory-alone” condition), and one in both the auditory and visual components were presented (the “audiovisual” condition). The noise levels were also varied, so that on some trials, the noise was very loud relative to the loudness of the words, and on other trials, the noise was very soft relative to the words. Sumby and Pollack (1954) found that the accuracy of identifying the spoken words was much higher for the audiovisual condition than it was in the auditory-alone condition. In addition, the pattern of results was consistent with the Principle of Inverse Effectiveness: The advantage gained by audiovisual presentation was highest when the auditory-alone condition performance was lowest (i.e., when the noise was loudest). At these noise levels, the audiovisual advantage was considerable: It was estimated that allowing the participant to see the speaker was equivalent to turning the volume of the noise down by over half. Clearly, the audiovisual advantage can have dramatic effects on behavior. Another phenomenon using audiovisual speech is a very famous illusion called the “McGurk effect” (named after one of its discoverers). In the classic formulation of the illusion, a movie is recorded of a speaker saying the syllables “gaga.” Another movie is made of the same speaker saying the syllables “baba.” Then, the auditory portion of the “baba” movie is dubbed onto the visual portion of the “gaga” movie. This combined stimulus is presented to participants, who are asked to report what the speaker in the movie said. McGurk and MacDonald (1976) reported that 98 percent of their participants reported hearing the syllable “dada”—which was in neither the visual nor the auditory components of the stimulus. These results indicate that when visual and auditory information about speech is integrated, it can have profound effects on perception. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2117 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2117 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2117 TRY ITTRY IT An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2117 Tactile/Visual Interactions in Body Ownership Not all multisensory integration phenomena concern speech, however. One particularly compelling multisensory illusion involves the integration of tactile and visual information in the perception of body ownership. In the “rubber hand illusion” (Botvinick & Cohen, 1998), an observer is situated so that one of his hands is not visible. A fake rubber hand is placed near the obscured hand, but in a visible location. The experimenter then uses a light paintbrush to simultaneously stroke the obscured hand and the rubber hand in the same locations. For example, if the middle finger of the obscured hand is being brushed, then the middle finger of the rubber hand will also be brushed. This sets up a correspondence between the tactile sensations (coming from the obscured hand) and the visual sensations (of the rubber hand). After a short time (around 10 minutes), participants report feeling as though the rubber hand “belongs” to them; that is, that the rubber hand is a part of their body. This feeling can be so strong that surprising the participant by hitting the rubber hand with a hammer often leads to a reflexive withdrawing of the obscured hand—even though it is in no danger at all. It appears, then, that our awareness of our own bodies may be the result of multisensory integration. Crossmodal Phenomena Crossmodal phenomena are distinguished from multimodal phenomena in that they concern the influence one sensory modality has on the perception of another. Figure 7. Ventriloquists are able to trick us into believing that what we see and what we hear are the same where, in truth, they are not. [Image: Indiapuppet] LINK TO LEARNINGLINK TO LEARNING Participate in the double-flash experiment here. Take a look at the bouncing balls illusion here. Visual Influence on Auditory Localization A famous (and commonly experienced) crossmodal illusion is referred to as “the ventriloquism effect.” When a ventriloquist appears to make a puppet speak, she fools the listener into thinking that the location of the origin of the speech sounds is at the puppet’s mouth. In other words, instead of localizing the auditory signal (coming from the mouth of a ventriloquist) to the correct place, our perceptual system localizes it incorrectly (to the mouth of the puppet). Why might this happen? Consider the information available to the observer about the location of the two components of the stimulus: the sounds from the ventriloquist’s mouth and the visual movement of the puppet’s mouth. Whereas it is very obvious where the visual stimulus is coming from (because you can see it), it is much more difficult to pinpoint the location of the sounds. In other words, the very precise visual location of mouth movement apparently overrides the less well-specified location of the auditory information. More generally, it has been found that the location of a wide variety of auditory stimuli can be affected by the simultaneous presentation of a visual stimulus (Vroomen & De Gelder, 2004). In addition, the ventriloquism effect has been demonstrated for objects in motion: The motion of a visual object can influence the perceived direction of motion of a moving sound source (Soto-Faraco, Kingstone, & Spence, 2003). Auditory Influence on Visual Perception A related illusion demonstrates the opposite effect: where sounds have an effect on visual perception. In the double-flash illusion, a participant is asked to stare at a central point on a computer monitor. On the extreme edge of the participant’s vision, a white circle is briefly flashed one time. There is also a simultaneous auditory event: either one beep or two beeps in rapid succession. Remarkably, participants report seeing two visual flashes when the flash is accompanied by two beeps; the same stimulus is seen as a single flash in the context of a single beep or no beep (Shams, Kamitani, & Shimojo, 2000). In other words, the number of heard beeps influences the number of seen flashes! Another illusion involves the perception of collisions between two circles (called “balls”) moving toward each other and continuing through each other. Such stimuli can be perceived as either two balls moving through each other or as a collision between the two balls that then bounce off each other in opposite directions. Sekuler, Sekuler, and Lau (1997) showed that the presentation of an auditory stimulus at the time of contact between the two balls strongly influenced the perception of a collision event. In this case, the perceived sound influences the interpretation of the ambiguous visual stimulus. Crossmodal Speech Several crossmodal phenomena have also been discovered for speech stimuli. These crossmodal speech effects usually show altered perceptual processing of unimodal stimuli (e.g., acoustic patterns) by virtue of prior experience with the alternate unimodal stimulus (e.g., optical patterns). For example, Rosenblum, Miller, and Sanchez (2007) conducted an experiment examining the ability to become familiar with a person’s voice. Their first interesting finding was unimodal: Much like what happens when someone repeatedly hears a person speak, perceivers can become familiar with the “visual voice” of a speaker. That is, they can become familiar with the https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/10/27203253/ventril https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/10/27203253/ventril http://www.cns.atr.jp/~kmtn/soundInducedIllusoryFlash2/ http://www.michaelbach.de/ot/mot-bounce/index.html GLOSSARYGLOSSARY closure:closure: organizing our perceptions into complete objects rather than as a series of parts crossmodal phenomenacrossmodal phenomena: effects that concern the influence of the perception of one sensory modality on the perception of another double flash illusiondouble flash illusion: the false perception of two visual flashes when a single flash is accompanied by two auditory beeps figure-ground relationship:figure-ground relationship: segmenting our visual world into figure and ground Gestalt psychology:Gestalt psychology: field of psychology based on the idea that the whole is different from the sum of its parts< good continuation:good continuation: (also, continuity) we are more likely to perceive continuous, smooth flowing lines rather than jagged, broken lines integratedintegrated: the process by which the perceptual system combines information arising from more than one modality McGurk effectMcGurk effect: an effect in which conflicting visual and auditory components of a speech stimulus result in an illusory percept multimodalmultimodal: of or pertaining to multiple sensory modalities multimodal perceptionmultimodal perception: the effects that concurrent stimulation in more than one sensory modality has on the perception of events and objects in the world multimodal phenomenamultimodal phenomena: effects that concern the binding of inputs from multiple sensory modalities pattern perception:pattern perception: ability to discriminate among different figures and shapes perceptual hypothesis:perceptual hypothesis: educated guess used to interpret sensory information principle of closure:principle of closure: organize perceptions into complete objects rather than as a series of parts proximity:proximity: things that are close to one another tend to be grouped together rubber hand illusionrubber hand illusion: the false perception of a fake hand as belonging to a perceiver, due to multimodal sensory information sensory modalitiessensory modalities: a type of sense; for example, vision or audition similarity:similarity: things that are alike tend to be grouped together unimodalunimodal: of or pertaining to a single sensory modality person’s speaking style simply by seeing that person speak. Even more astounding was their crossmodal finding: Familiarity with this visual information also led to increased recognition of the speaker’s auditory speech, to which participants had never had exposure. Similarly, it has been shown that when perceivers see a speaking face, they can identify the (auditory-alone) voice of that speaker, and vice versa (Kamachi, Hill, Lander, & Vatikiotis-Bateson, 2003; Lachs & Pisoni, 2004a, 2004b, 2004c; Rosenblum, Smith, Nichols, Lee, & Hale, 2006). In other words, the visual form of a speaker engaged in the act of speaking appears to contain information about what that speaker should sound like. Perhaps more surprisingly, the auditory form of speech seems to contain information about what the speaker should look like. THINK IT OVERTHINK IT OVER In the late 17th century, a scientist named William Molyneux asked the famous philosopher John Locke a question relevant to modern studies of multisensory processing. The question was this: Imagine a person who has been blind since birth, and who is able, by virtue of the sense of touch, to identify three dimensional shapes such as spheres or pyramids. Now imagine that this person suddenly receives the ability to see. Would the person, without using the sense of touch, be able to identify those same shapes visually? Can modern research in multimodal perception help answer this question? Why or why not? How do the studies about crossmodal phenomena inform us about the answer to this question? Figure 1. This 3-D street art demonstrates how artists utilize illusions to portray depth on a 2-D sidewalk. Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Modification, adaptation, and original content. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution • Modification of content on multi-modal perception. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike CC licensed content, Shared previouslyCC licensed content, Shared previously • Perception Poster Show Concept. Authored byAuthored by: Jon Ashcroft. Located atLocated at: https://www.flickr.com/photos/theilluminated/5704563713. LicenseLicense: CC BY: Attribution • Gestalt Principles of Psychology. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.49:cOcxAR_r@5/Gestalt-Principles-of-Percepti#Figure_05_06_Continuity. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/content/col11629/latest/. • Multi-Modal Perception. Authored byAuthored by: Lorin Lachs. Provided byProvided by: California State University, Fresno. Located atLocated at: http://nobaproject.com/modules/multi-modal-perception. ProjectProject: The Noba Project. LicenseLicense: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike All rights reserved contentAll rights reserved content • Perceiving is Believing - Crash Course Psychology #7. Provided byProvided by: CrashCourse. Located atLocated at: https://www.youtube.com/watch?v=n46umYA_4dM. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License • The McGurk Effect. Provided byProvided by: BBC. Located atLocated at: https://youtu.be/G-lN8vWm3m0?t=32s. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License • The Rubber Hand Illusion. Provided byProvided by: BBC. Located atLocated at: https://youtu.be/sxwn1w7MJvk. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License ILLUSIONS LEARNING OBJECTIVESLEARNING OBJECTIVES • Explain how and why psychologists use illusions Why Illusions? Psychologists have analyzed perceptual systems for more than a century. Vision and hearing have received the most attention by far, but other perceptual systems, like those for smell taste movement, balance, touch, and pain, have also been studied extensively. Perception scientists use a variety of approaches to study these systems—they design experiments, study neurological patients with damaged brain regions, and create perceptual illusions that toy with the brain’s efforts to interpret the sensory world. Creation and testing of perceptual illusions has been a fruitful approach to the study of perception—particularly visual perception—since the early days of psychology. People often think that visual illusions are simply amusing tricks that provide us with entertainment. Many illusions are fun to experience, but perception scientists create illusions based on their understanding of the perceptual system. Once they have created a successful illusion, the scientist can explore what people experience, what parts of the brain are involved in interpretation of the illusion, and what variables increase or diminish the strength of the illusion. Scientists are not alone in this interest. Visual artists have discovered and used many illusion-producing principles for centuries, allowing them to create the experience of depth, movement, light and shadow, and relative size on two- dimensional canvases. Depth Illusions When we look at the world, we are not very good at detecting the absolute qualities of things—their exact size or color or shape. What we are very good at is judging objects in the context of other objects and conditions. Let’s take a look at a few illusions to see how they are based on insights about our perception. Look at Figure 2 below. Which of the two horizontal yellow lines looks wider, the top one or the bottom one? https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by-nc-sa/4.0/ https://www.flickr.com/photos/theilluminated/5704563713 https://creativecommons.org/licenses/by/4.0/ http://cnx.org/contents/Sr8Ev5Og@5.49:cOcxAR_r@5/Gestalt-Principles-of-Percepti#Figure_05_06_Continuity https://creativecommons.org/licenses/by/4.0/ http://nobaproject.com/modules/multi-modal-perception https://creativecommons.org/licenses/by-nc-sa/4.0/ https://creativecommons.org/licenses/by-nc-sa/4.0/ https://www.youtube.com/watch?v=n46umYA_4dM https://youtu.be/G-lN8vWm3m0?t=32s https://youtu.be/sxwn1w7MJvk https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/02/14154724/Horizontal_3d_graffiti_%C5%81%C3%B3d%C5%BA_Schillera_Passage https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/02/14154724/Horizontal_3d_graffiti_%C5%81%C3%B3d%C5%BA_Schillera_Passage Figure 2. The Ponzo Illusion. Most people experience the top line as wider. They are both exactly the same length. This experience is called the Ponzo illusion. Even though you know that the lines are the same length, it is difficult to see them as identical. Our perceptual system takes the context into account, here using the converging “railroad tracks” to produce an experience of depth. Then, using some impressive mental geometry, our brain adjusts the experienced length of the top line to be consistent with the size it would have if it were that far away: if two lines are the same length on my retina, but different distances from me, the more distant line must be in reality longer. You experience a world that “makes sense” rather than a world that reflects the actual objects in front of you. There are many depth illusions. It is difficult to see the drawing on the left below as a two-dimensional figure. The converging lines and smaller square at the center seem to coax our perceptual systems into seeing depth, even though we know that the drawing is flat. This urge to see depth is probably so strong because our ability to use two-dimensional information to infer a three dimensional world is essential for allowing us to operate in the world. The picture on the right below is a driving tunnel, something you would need to process at high speed if you were in a car going through it. Your quick and detailed use of converging lines and other cues allows you to make sense of this 3-D world. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/02/07210125/Ponzo_illusion.gif https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/02/07210125/Ponzo_illusion.gif Figure 3. Understanding depth enables us to function in a 3-dimensional world. Light and Size Illusions Depth is not the only quality in the world that shows how we adjust what we experience to fit the surrounding world. Look at the two gray squares in the figure below. Which one looks darker? Figure 4. Which gray square appears darker? Most people experience the square on the right as the darker of the two gray squares. You’ve probably already guessed that the squares are actually identical in shade, but the surrounding area—black on the left and white on the right—influence how our perceptual systems interpret the gray area. In this case, the greater difference in shading between the white surrounding area and the gray square on the right results in the experience of a darker square. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/02/07210639/Screen-Shot-2017-02-07-at-3.04.55-PM https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/02/07210639/Screen-Shot-2017-02-07-at-3.04.55-PM https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/02/07211928/Simultaneous_Contrast https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/02/07211928/Simultaneous_Contrast Here is another example below. The two triangular figures are identical in shade, but the triangle on the left looks lighter against the dark background of the cross when compared to the triangle in the white area on the right. Figure 5. Benary Cross Our visual systems work with more than simple contrast. They also use our knowledge of how the world works to adjust our perceptual experience. Look at the checkerboard below. There are two squares with letters in them, one marked “A” and the other “B”. Which one of those two squares is darker? https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/02/07212941/569px-Benary_Cross.svg_ https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/02/07212941/569px-Benary_Cross.svg_ An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=3576 Figure 6. Which looks darker, A or B? This seems like an easy comparison, but the truth is that squares A and B are identical in shade. Our perceptual system adjusts our experience by taking some visual information into account. First, “A” is one of the “dark squares” and “B” is a “light square” if we take the checkerboard pattern into account. Perhaps even more impressive, our visual systems notice that “B” is in a shadow. Object in a shadow appear darker, so our experience is adjusted to take account of effect of the shadow, resulting in perceiving square B as being lighter than square A, which sits in the bright light. And if you really don’t believe your eyes, take a look at a video showing the same color tiles here. One final illusion takes us back to adjustment for size. Look at the two sets of circles below. Your task is to adjust the center circle on the left so it is the same actual size as the center circle on the right. The surrounding circles will not change in size, though the right of circles will expand to accommodate the size of the center circle. Use the slide bar with the label “Size of left circle” to make your adjustments. When you are satisfied with your adjustment, check your accuracy by clicking on the “Verify Diameter” button. Click “Reset” to try again. This illusion is called the Ebbinghaus illusion, created by Hermann Ebbinghaus, one of the early founders of experimental psychology. It is shown again below. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/02/07213735/Optical.greysquares.arp_ https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/02/07213735/Optical.greysquares.arp_ https://www.youtube.com/watch?v=CRvo1jRXiI8 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=3576 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=3576 TRY ITTRY IT LINK TO LEARNINGLINK TO LEARNING If you want to explore more visual illusions, here is a great site with dozens of interesting illusions created by Michael Bach. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=3576 In this version of the illusion, most people see the circle on the right as larger than the one on the left. The two orange circles are exactly the same size. The Ebbinghaus illusion again illustrates the tendency of our perceptual systems to adjust our experience of the world to the surrounding context. How do you think a psychologist might use the Ebbinghaus illusion to learn about mental processes or behavior (shown again below)? Read on to see an actual example from a psychologist at Colorado State University. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/02/02202255/650px-Mond-vergleich.svg_ http://www.michaelbach.de/ot/ Figure 1. Do you suspect that the perceived size of a golf hole will affect putting performance? Ebbinghaus in the Real World Imagine that you are in a golf competition in which you are putting against someone with the same experience and skill that you have. There is one problem: Your opponent gets to putt into a hole that is 10% larger than the hole you have to use. You’d probably think that the competition was unfairly biased against you. Now imagine a somewhat different situation. You and your opponent are about equal in ability and the holes you are using are the same size, but the hole that your opponent is using looks 10% larger than the one you are using. Would your opponent have an unfair advantage now? If you read the earlier section on the Ebbinghaus effect, you have an idea how psychologists could exploit your perceptual system (and your opponent’s) to test this very question. Psychologist Jessica Witt and her colleagues Sally Linkenauger and Dennis Proffitt recruited research participants with no unusual golf experience to participate in a putting task. They competed against themselves rather than against another person. The experimenters made the task challenging by using a hole with a 2-inch diameter, which is about half the diameter of the hole you will find on a golf course. An overhead projector mounted on the ceiling of their lab allowed them to project Ebbinghaus’s circles around the putting hole. Some participants saw the putting hole surrounded by circles that were smaller than the hole in the center; the other half saw surrounding black circles that were larger. Participants putted from about 11½ feet away. They took 10 putts in one condition, and then 10 in the other condition. Half of the participants putted with the large surrounding circles first and half saw the small surrounding circles first. This procedure is called counterbalancingcounterbalancing. If there is any advantage (e.g., getting better over time with practice) or disadvantage (e.g., getting tired of putting), counterbalancing assures that both conditions are equally exposed to the positive or negative effects of which task goes first or second. Failure to take account of this type of problem means that you may have a confounding variableconfounding variable—practice or fatigue—that influences performance. A confounding variable is something that could influence performance, but is not part of the study. We try to control (that is, neutralize) potentially confounding variables so they cannot be the cause of performance differences. So, for instance, if everyone did the large surrounding circles condition first and then the small surrounding circles, then differences in performance could be due to order of conditions (leading to practice or fatigue effects) rather than the size of the surrounding circles. By counterbalancing, we don’t get rid of the effects of practice or fatigue for any particular person, but—across all the participants—practice or fatigue should affect both conditions (both types of Ebbinghaus circles) equally. The experimenters wanted to know two things. First, did they actually produce the Ebbinghaus illusion? Remember: there is no guarantee that people see or think the way your theory says they should. So just before the participant started putting in a particular condition, he or she drew a circle using a computerized drawing tool, attempting to match the exact size of the putting hole. This is better than simply asking, “do you see the illusion?” The drawing task attempts to directly measure what they perceive. Second, the experimenters wanted to see if the perceived size of the hole influenced putting accuracy. They recorded the success or failure of each putt. Each participant could get a score of 0 to 10 successful putts in each condition. Methods Summary Recap the steps you’ve read about thus far: 1. The participant practices putting to get used to the task. 2. The participant completes the first condition (large surrounding circles for half of the participants and small surrounding circles for the other half). https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/02/14025440/ball-1842170_1920 https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/02/14025440/ball-1842170_1920 TRY ITTRY IT Now that you know the details of Jessica Witt’s experiment, see if you can answer the following questions. ClickNow that you know the details of Jessica Witt’s experiment, see if you can answer the following questions. Click on the option you think is correct and then click the ‘Show Answer’ link to see if you’re right.on the option you think is correct and then click the ‘Show Answer’ link to see if you’re right. Question 1: What is the independent variable as described in this study?Question 1: What is the independent variable as described in this study? The size of the putting hole is the independent variable. The size of the circles surrounding the putting hole is the independent variable. The distance the person had to putt is the independent variable. There are two independent variables: the size of the putting hole and the size of the surrounding circles. AnswerAnswer An INDEPENDENT VARIABLE is something intentionally manipulated (changed) by the experimenter. To test the effect of the Ebbinghaus illusion, the experimenters had participants putt into holes surrounded by larger circles and smaller circles. This “manipulation” of the size of the surrounding holes is the independent variable. Question 2: What is the dependent variable in this study?Question 2: What is the dependent variable in this study? The number of successful putts is the dependent variable. The size of the circle drawn by the participant is the dependent variable. The size of the putting hole is the dependent variable. There are two dependent variables: the number of successful putts and the size of the circle drawn by the participants are both dependent variables. AnswerAnswer A DEPENDENT VARIABLE is some behavior or thought process measured by the experimenter. This study had two dependent variables: • (a) the size of the circle drawn by the participant • (b) the number of successful putts Both dependent variables were measured for each condition, so each participant drew 2 circles and had 0 to 10 successful putts in both the large surrounding circles condition and the small surrounding circles condition. TRY ITTRY IT Question 3: How did the participants perceive the holes?Question 3: How did the participants perceive the holes? Resize the bars below by clicking and dragging them to show your predicted results when the subjects were asked to draw the circles. Make a general prediction based on your understanding of the experiment. ◦ The participant draws a circle corresponding to his or her estimation of the actual size of the putting hole. This allows the experimenters to determine if the Ebbinghaus effect actually occurred. ◦ The participant putts 10 times in this condition. 3. Participant completes the second condition (whichever condition they have not yet done). ◦ The participant draws a circle corresponding to his or her estimation of the actual size of the putting hole. ◦ The participant putts 10 times in this condition. Now see if you can guess the results of this study. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=3576 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=3576 AnswerAnswer This question tested whether or not the Ebbinghaus effect was produced in this experiment. If there is no difference between the bars, that would mean that participants didn’t experience the Ebbinghaus illusion. The exact height of the bars is not important here, but the relative heights should look something like this: The taller bar on the right means that the center putting hole looks larger when it is surrounded by smaller circles than when the same hole is surrounded by large circles: The Ebbinghaus illusion. This result was important because the reasoning behind the experiment was dependent on successfully producing the Ebbinghaus illusion. There is a technical term for a dependent variable that is used to determine if your independent variable is actually working: a manipulation checkmanipulation check. Good experimenters use manipulation checks to be sure they aren’t fooling themselves into believing that they have done something that really didn’t work. Question 4: Can you guess how well the participants putted?Question 4: Can you guess how well the participants putted? Resize the bars below by clicking and dragging them to show your predicted results when the subjects putted. AnswerAnswer This question lets you check out your skills as a psychologist. The description of the experiment did not include the researchers’ hypothesis, so you have to decide for yourself what you think is going to happen. The three possible patterns of results are shown below. The graph you drew fit one of these patterns. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/02/23070233/bars11 TRY ITTRY IT Before we show you the actual results of the study, write our your prediction. Do you think the illusion affected putting performance? Why or why not? Explain your answer in the text box below: AnswerAnswer Until now, we haven’t told you exactly how the Ebbinghaus illusion was predicted to influence putting—only that the experimenters thought it would have some sort of influence. So here is what they said. The experimenters thought that the perceived size of the hole would affect the SELF-CONFIDENCE of the person as he or she putted. If you are putting into a larger hole (or what is PERCEIVED as a larger hole) you should be more confident that you will sink your putt. Remember, this is just a prediction based on the experimenters’ reasoning. Their ideas came from interviewing skilled athletes who claimed that objects seemed larger and time seemed to slow down as they gained skill. If the ball you have to catch is bigger or the person blocking you is slower, you can perform at a higher level. The experimenters could be right or they could be wrong. Your own reasoning might be different than that of the experimenters. For instance, perhaps you thought that people would be MORE CAREFUL if they thought the hole was smaller. That would be a perfectly fine hypothesis. Interestingly, it makes the opposite prediction from the experimenters’ self-confidence hypothesis. This “careful putting with smaller holes” theory predicts that people should putt better when they perceive the hole as smaller (i.e., when the surrounding circles are large). The experimenters’ “more confidence with larger holes” hypothesis predicts that people should putt better when they perceive the hole as larger. Here are the actual results. First, the hole was perceived as larger when it was surrounded by smaller holes, so there is evidence that they successfully produced the Ebbinghaus illusion. Second, the experimenters predicted that participants would be more successful when the hole seemed larger (i.e., surrounded by smaller circles). Consistent with these predictions, the results looked like this: This is not the only experiment that has used a sports context to study the effects of illusions. Other experiments have shown that people hit softballs better when the balls are perceived as larger. People score higher in darts when the board appears larger. Athletes kick field goals and return tennis balls more successfully when the goal posts or tennis balls appear larger. In all of these studies, the balls or boards or goal posts were not actually larger, but they were perceived as larger because the experimenters created illusions. Skilled athletes often report https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/02/23070056/bars21 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=3576 LINK TO LEARNINGLINK TO LEARNING Watch this interview with Psychologist Jessica Witt to see her talk about how her research utilizing the Ebbinghaus illusion impacts a golfer’s perception and performance. You can also read about more about similar variations of her research here. that targets appear larger or time slows down when they are “in the zone”, as if practice and skill create their own perceptual illusions that increase confidence and make difficult challenges feel easier. A Final Note: Science Doesn’t Always Produce Simple Results Professor Witt’s study had interesting results; however, they weren’t quite as simple as we have made them seem. The researchers actually had two different hole sizes: 2 inches and 4 inches. The Ebbinghaus circles were adjusted to be relatively larger or smaller than the putting hole. The Ebbinghaus illusion worked for the smaller (2 inch) putting holes, but not for the larger (4 inch) putting holes. In other words, when people drew the circles as they perceived them (the “manipulation check” dependent variable), they drew different sized circles for the 2 inch holes (the Ebbinghaus illusion), but the same size circles for the 4 inch holes (no Ebbinghaus illusion). For the larger (4 inch) putting holes, putting accuracy was the same for the two different conditions. This didn’t bother the experimenters, because—as we have already noted—the participants did not experience the Ebbinghaus illusion with the larger holes. If the holes were perceived as the same, then self-confidence should not have been affected and, in turn, putting should not have been better in one condition than the other. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/02/23070152/bars3 http://www.apa.org/science/about/psa/2016/12/action-visual-perception.aspx An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=3576 In the research paper, the experimenters suggest a few technical reasons that the larger hole might not have produced the Ebbinghaus illusion, but they admit that they have no definitive explanation. That’s okay. Science often yields messy results—and these can be the basis for new experiments and sometimes for really interesting discoveries. The world is not as simple as our theories try to make it seem. Happily, in science, as in many aspects of life, you learn more from your failures than your successes, so good scientists don’t try to hide from results they don’t expect. Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Ebbinghaus Application and Text on Illusions. Authored byAuthored by: Patrick J Carroll. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution CC licensed content, Shared previouslyCC licensed content, Shared previously • Mond-Vergleich image. Authored byAuthored by: Fibonacci. Located atLocated at: https://commons.wikimedia.org/wiki/File:Mond-vergleich.svg. ProjectProject: Wikimedia. LicenseLicense: CC BY-SA: Attribution-ShareAlike • A hole in the head: Golf and Perception. Authored byAuthored by: sciencentral. Located atLocated at: https://www.youtube.com/watch?v=XDNfTUOSjFw. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License • golf picture. Authored byAuthored by: coffee. Provided byProvided by: Pixabay. Located atLocated at: https://pixabay.com/en/ball-golf-golf-ball-golf-course-1842170/. LicenseLicense: CC0: No Rights Reserved • Ponzo Illusion. Authored byAuthored by: Wikipedia. Located atLocated at: https://commons.wikimedia.org/wiki/File:Ponzo_illusion.gif. LicenseLicense: Public Domain: No Known Copyright • Contrast Illusion. Authored byAuthored by: Paaliaq. Provided byProvided by: Wikimedia. Located atLocated at: https://commons.wikimedia.org/wiki/Category:Contrast_illusions#/media/File:Simultaneous_Contrast . LicenseLicense: CC BY-SA: Attribution- ShareAlike • Benary Cross Illusion. Provided byProvided by: Wikimedia. Located atLocated at: https://commons.wikimedia.org/wiki/Category:Contrast_illusions#/media/File:Benary_Cross.svg. LicenseLicense: Public Domain: No Known Copyright • Checkerboard Illusion. Authored byAuthored by: Adrian Pingstone . Provided byProvided by: Wikipedia. Located atLocated at: https://commons.wikimedia.org/wiki/File:Optical.greysquares.arp . LicenseLicense: Public Domain: No Known Copyright • Horizontal 3D grafitti. Provided byProvided by: Wikimedia. Located atLocated at: https://commons.wikimedia.org/wiki/File:Horizontal_3d_graffiti,_%C5%81%C3%B3d%C5%BA_Schillera_Passage . LicenseLicense: CC BY-SA: Attribution-ShareAlike Public domain contentPublic domain content • Baltimore Harbor Tunnel. Authored byAuthored by: ErgoSum88. Provided byProvided by: Wikimedia. Located atLocated at: https://commons.wikimedia.org/wiki/Category:Centered_tunnel_perspective#/media/File:Baltimore_Harbor_Tunnel_I-895_02.JPG. LicenseLicense: Public Domain: No Known Copyright • Simple shape square optical illusion. Provided byProvided by: Wikimedia. Located atLocated at: https://commons.wikimedia.org/wiki/Category:Optical_illusions#/media/File:PSM_V54_D322_Simple_shape_creating_optical_illusion_2 . LicenseLicense: Public Domain: No Known Copyright • Ebbinghaus Illusion. Provided byProvided by: Wikimedia. Located atLocated at: https://en.wikipedia.org/wiki/File:Mond-vergleich.svg. LicenseLicense: Public Domain: No Known Copyright PUTTING IT TOGETHER: SENSATION AND PERCEPTION LEARNING OBJECTIVESLEARNING OBJECTIVES In this module, you learned to • differentiate between sensation and perception • explain the process of vision and how people see color and depth • explain the basics of hearing • describe the basic anatomy and functions of taste, smell, touch, pain, and the vestibular sense • define perception and give examples of gestalt principles and multimodal perception In this module, you learned about the way our senses work and the impact they have on our perception of the world. Our impressive sensory abilities allow us to experience the most enjoyable and most miserable experiences, as well as everything in between. Our eyes, ears, nose, tongue and skin provide an interface for the brain to interact with the world around us. While there is simplicity in covering each sensory modality independently, we are organisms that have evolved the ability to process multiple modalities as a unified experience. While the information covered in this module may initially seem straightforward and stagnant, you saw in the example from Jessica Witt’s research on perception that a person’s perception of the size of a golf hole can impact their performance. The ways that perception can alter our behavior and the impact this has on mental processes is of particular interest to psychologists. https://creativecommons.org/licenses/by/4.0/ https://commons.wikimedia.org/wiki/File:Mond-vergleich.svg https://creativecommons.org/licenses/by-sa/4.0/ https://www.youtube.com/watch?v=XDNfTUOSjFw https://pixabay.com/en/ball-golf-golf-ball-golf-course-1842170/ https://creativecommons.org/about/cc0 https://commons.wikimedia.org/wiki/File:Ponzo_illusion.gif https://creativecommons.org/about/pdm https://commons.wikimedia.org/wiki/Category:Contrast_illusions#/media/File:Simultaneous_Contrast https://creativecommons.org/licenses/by-sa/4.0/ https://creativecommons.org/licenses/by-sa/4.0/ https://commons.wikimedia.org/wiki/Category:Contrast_illusions#/media/File:Benary_Cross.svg https://creativecommons.org/about/pdm https://commons.wikimedia.org/wiki/File:Optical.greysquares.arp https://creativecommons.org/about/pdm https://commons.wikimedia.org/wiki/File:Horizontal_3d_graffiti,_%C5%81%C3%B3d%C5%BA_Schillera_Passage https://creativecommons.org/licenses/by-sa/4.0/ https://commons.wikimedia.org/wiki/Category:Centered_tunnel_perspective#/media/File:Baltimore_Harbor_Tunnel_I-895_02.JPG https://creativecommons.org/about/pdm https://commons.wikimedia.org/wiki/Category:Optical_illusions#/media/File:PSM_V54_D322_Simple_shape_creating_optical_illusion_2 https://creativecommons.org/about/pdm https://en.wikipedia.org/wiki/File:Mond-vergleich.svg https://creativecommons.org/about/pdm Figure 1. Google Cardboard. A video element has been excluded from this version of the text. You can watch it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2947 Figure 2. Pincushion distortion. Figure 3. Barrel distortion. One current area of interest is the influence of psychological principles on virtual reality design. Think about it. How can designers create a 3-dimensional world on a 2-dimensional plane? They must first consider the way that we interpret visual cues and how we see depth. Consider Google Cardboard. In 2014, two Google engineers created a cardboard viewer lens that allows users to place their smartphones inside and view the world as if they entered a virtual reality. This was a huge leap forward in reducing the cost of and increasing access to virtual reality. But how did they do it? In order to feel like you are immersed in the gaming world, you need to remove the distractions that exist outside of the immediate visual field. Hence, the box around the phone. You also need to feel like you are inside of the world, so the box includes lenses that adjust your focal point and magnify the picture on the screen (Figure 1). You also need the world to be 3-dimensional. As you learned, your eyes rely on several monocular and binocular cues in order to see depth. Binocular disparity describes the slightly unique view of the world we see from each of our two eyes (which explains why if you hold an object near your face and close one eye, then open it and close the other, that object appears to move). To create this effect, developers put a barrier between the left and right visual fields and split the screen in two, so that the image on the screen is slightly different. The picture on your phone shows up like this: Because you are viewing the image through magnified lenses, there is a distortion called the pincushion distortion, which stretches the image in the corners of the view. To counteract that and make the work appear normal, developers apply a barrel distortion to the viewer, which explains why you see the image in the video with the pinched corners. Advances in virtual reality are also important to psychology because virtual reality is a treatment method used to help those with psychological disorders. Consider PTSD or phobias, for example. In a virtual world, a counselor can create situations and experiences designed to recreate the triggers for specific behaviors and assist the client in using coping mechanisms to deal with threatening situations. Virtual reality therapy can be used in numerous ways as a type of exposure therapy, even assisting people with autism as they practice recognizing and interpreting social cues or helping those with depression to make choices to help them prevent negative thoughts. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/11/26142949/Google-Cardboard https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/11/26142949/Google-Cardboard https://vr.google.com/cardboard/ https://courses.lumenlearning.com/cochise-psychology/?p=2947#pb-interactive-content https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/11/26150327/768px-Pincushion_distortion.svg_ https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/11/26150327/768px-Pincushion_distortion.svg_ Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Putting It Together: Sensation and Perception. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike CC licensed content, Shared previouslyCC licensed content, Shared previously • Google Cardboard VR with Camera Viewer. Authored byAuthored by: sndrv. Provided byProvided by: Flickr. Located atLocated at: https://www.flickr.com/photos/sndrv/16905172090. LicenseLicense: CC BY: Attribution • Distortion images. Authored byAuthored by: WolfWings. Provided byProvided by: Wikimedia. Located atLocated at: https://en.wikipedia.org/wiki/Distortion_(optics). LicenseLicense: Public Domain: No Known Copyright • Google Cardboard. Provided byProvided by: Wikipedia. Located atLocated at: https://en.wikipedia.org/wiki/Google_Cardboard. LicenseLicense: CC BY-SA: Attribution-ShareAlike • Introductory Paragraph. Authored byAuthored by: Adam John Privitera . Provided byProvided by: Chemeketa Community College. Located atLocated at: http://nobaproject.com/modules/sensation-and-perception. ProjectProject: The Noba Project. LicenseLicense: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike Public domain contentPublic domain content • Google Cardboard image. Authored byAuthored by: Evan Amos. Located atLocated at: https://en.wikipedia.org/wiki/Google_Cardboard#/media/File:Google-Cardboard . LicenseLicense: Public Domain: No Known Copyright DISCUSSION: SENSATION AND PERCEPTION Cultural Influences on Perception STEP 1STEP 1: Respond to the following prompt in a primary post of at least 150-200 words: Sensation refers to an actual event; perception refers to how we interpret the event. What are some cultural differences that might affect responses to particular stimuli? Create a post using examples from the text as well as your own experiences. STEP 2STEP 2: Thoughtfully respond to a minimum of 2 classmates with posts of at least 100 words each. Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Discussion: Sensation and Perception. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution CC licensed content, Shared previouslyCC licensed content, Shared previously • Discussion idea. Authored byAuthored by: Terry Davis . Provided byProvided by: Wiley College. LicenseLicense: CC BY: Attribution https://creativecommons.org/licenses/by-nc-sa/4.0/ https://www.flickr.com/photos/sndrv/16905172090 https://creativecommons.org/licenses/by/4.0/ https://en.wikipedia.org/wiki/Distortion_(optics) https://creativecommons.org/about/pdm https://en.wikipedia.org/wiki/Google_Cardboard https://creativecommons.org/licenses/by-sa/4.0/ http://nobaproject.com/modules/sensation-and-perception https://creativecommons.org/licenses/by-nc-sa/4.0/ https://creativecommons.org/licenses/by-nc-sa/4.0/ https://en.wikipedia.org/wiki/Google_Cardboard#/media/File:Google-Cardboard https://creativecommons.org/about/pdm https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ MODULE 5: STATE OF CONSCIOUSNESS WHY IT MATTERS: STATES OF CONSCIOUSNESS Sleep, which we all experience, is a quiet and mysterious pause in our daily lives. Two sleeping children are depicted in this 1895 oil painting titled Zwei schlafende Mädchen auf der Ofenbank, which translates as “two sleeping girls on the stove,” by Swiss painter Albert Anker. Our lives involve regular, dramatic changes in the degree to which we are aware of our surroundings and our internal states. While awake, we feel alert and aware of the many important things going on around us. Our experiences change dramatically while we are in deep sleep and once again when we are dreaming. Sometimes, we seek to alter our awareness and experience by using psychoactive drugs; that is, drugs that alter the central nervous system and produce a change of consciousness or a deep meditative state. Consciousness is an awareness of external and internal stimuli. As discussed in the module on the biology of psychology, the brain activity during different phases of consciousness produces characteristic brain waves, which can be observed by electroencephalography (EEG) and other types of analysis. This module will discuss states of consciousness with a particular emphasis on sleep. You’ll learn about the different stages of sleep, sleep disorders as well as the altered states of consciousness produced by psychoactive drugs, hypnosis, and meditation. AnswerAnswer Aggarwal, S. K., Carter, G. T., Sullivan, M. D., ZumBrunnen, C., Morrill, R., & Mayer, J. D. (2009). Medicinal use of cannabis in the United States: Historical perspectives, current trends, and future directions. Journal of Opioid Management, 5, 153–168. Alhola, P. & Polo-Kantola, P. (2007). Sleep Deprivation: Impact on cognitive performance. Neuropsychiatric Disease and Treatment, 3, 553–557. Alladin, A. (2012). Cognitive hypnotherapy for major depressive disorder. The American Journal of Clinical Hypnosis, 54, 275–293. American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Arlington, VA: Author. Aquina, C. T., Marques-Baptista, A., Bridgeman, P., & Merlin, M. A. (2009). Oxycontin abuse and overdose. Postgraduate Medicine, 121, 163–167. Arnulf, I. (2012). REM sleep behavior disorder: Motor manifestations and pathophysiology. Movement Disorders, 27, 677–689. Augustinova, M., & Ferrand, L. (2012). Suggestion does not de-automatize word reading: Evidence from the semantically based Stroop task. Psychonomic Bulletin & Review, 19, 521–527. Banks, S., & Dinges, D. F. (2007). Behavioral and physiological consequences of sleep restriction. Journal of Clinical Sleep Medicine, 3, 519–528. Bartke, A., Sun, L. Y., & Longo, V. (2013). Somatotropic signaling: Trade-offs between growth, reproductive development, and longevity. Physiological Reviews, 93, 571–598. Berkowitz, C. D. (2012). Sudden infant death syndrome, sudden unexpected infant death, and apparent life- threatening events. Advances in Pediatrics, 59, 183–208. Berry, R. B., Kryger, M. H., & Massie, C. A. (2011). A novel nasal excitatory positive airway pressure (EPAP) device for the treatment of obstructive sleep apnea: A randomized controlled trial. Sleep, 34, 479–485. Bixler, E. O., Kales, A., Soldatos, C. R., Kales, J. D., & Healey, S. (1979). Prevalence of sleep disorders in the Los Angeles metropolitan area. American Journal of Psychiatry, 136, 1257–1262. Bostwick, J. M. (2012). Blurred boundaries: The therapeutics and politics of medical marijuana. Mayo Clinic Proceedings, 87, 172–186. Brook, R. D., Appel, L. J., Rubenfire, M., Ogedegbe, G., Bisognano, J. D., Elliott, W. K., . . . Rajagopalan, S. (2013). Beyond medications and diet: Alternative approaches to lowering blood pressure: A scientific statement from the American Heart Association. Hypertension, 61, 1360–1383. Broughton, R., Billings, R., Cartwright, R., Doucette, D., Edmeads, J., Edwardh, M., . . . Turrell, G. (1994). Homicidal somnambulism: A case report. Sleep, 17, 253–264. Brown, L. K. (2012). Can sleep deprivation studies explain why human adults sleep? Current Opinion in Pulmonary Medicine, 18, 541–545. Burgess, C. R., & Scammell, T. E. (2012). Narcolepsy: Neural mechanisms of sleepiness and cataplexy. Journal of Neuroscience, 32, 12305–12311. Cai, D. J., Mednick, S. A., Harrison, E. M., Kanady, J. C., & Mednick, S. C. (2009). REM, not incubation, improves creativity by priming associative networks. Proceedings of the National Academy of Sciences, USA, 106, 10130–10134. Caldwell, K., Harrison, M., Adams, M., Quin, R. H., & Greeson, J. (2010). Developing mindfulness in college students through movement based courses: Effects on self-regulatory self-efficacy, mood, stress, and sleep quality. Journal of American College Health, 58, 433–442. Capellini, I., Barton, R. A., McNamara, P., Preston, B. T., & Nunn, C. L. (2008). Phylogenetic analysis of the ecology and evolution of mammalian sleep. Evolution, 62, 1764–1776. Cartwright, R. (2004). Sleepwalking violence: A sleep disorder, a legal dilemma, and a psychological challenge. American Journal of Psychiatry, 161, 1149–1158. Cartwright, R., Agargun, M. Y., Kirkby, J., & Friedman, J. K. (2006). Relation of dreams to waking concerns. Psychiatry Research, 141, 261–270. Casati, A., Sedefov, R., & Pfeiffer-Gerschel, T. (2012). Misuse of medications in the European Union: A systematic review of the literature. European Addiction Research, 18, 228–245. Chen, K. W., Berger, C. C., Manheimer, E., Forde, D., Magidson, J., Dachman, L., & Lejuez, C. W. (2013). Meditative therapies for reducing anxiety: A systematic review and meta-analysis of randomized controlled trials. Depression and Anxiety, 29, 545–562. Chokroverty, S. (2010). Overview of sleep & sleep disorders. Indian Journal of Medical Research, 131, 126–140. Christensen, A., Bentley, G. E., Cabrera, R., Ortega, H. H., Perfito, N., Wu, T. J., & Micevych, P. (2012). Hormonal regulation of female reproduction. Hormone and Metabolic Research, 44, 587–591. CNN. (1999, June 25). ‘Sleepwalker’ convicted of murder. Retrieved from http://www.cnn.com/US/9906/25/ sleepwalker.01/ Cropley, M., Theadom, A., Pravettoni, G., & Webb, G. (2008). The effectiveness of smoking cessation interventions prior to surgery: A systematic review. Nicotine and Tobacco Research, 10, 407–412. De la Herrán-Arita, A. K., & Drucker-Colín, R. (2012). Models for narcolepsy with cataplexy drug discovery. Expert Opinion on Drug Discovery, 7, 155–164. Del Casale, A., Ferracuti, S., Rapinesi, C., Serata, D., Sani, G., Savoja, V., . . . Girardi, P. (2012). Neurocognition under hypnosis: Findings from recent functional neuroimaging studies. International Journal of Clinical and Experimental Hypnosis, 60, 286–317. Elkins, G., Johnson, A., & Fisher, W. (2012). Cognitive hypnotherapy for pain management. The American Journal of Clinical Hypnosis, 54, 294–310. Ellenbogen, J. M., Hu, P. T., Payne, J. D., Titone, D., & Walker, M. P. (2007). Human relational memory requires time and sleep. Proceedings of the National Academy of Sciences, USA, 104, 7723–7728. Fell, J., Axmacher, N., & Haupt, S. (2010). From alpha to gamma: Electrophysiological correlates meditation- related states of consciousness. Medical Hypotheses, 75, 218–224. Fenn, K. M., Nusbaum, H. C., & Margoliash, D. (2003). Consolidation during sleep of perceptual learning of spoken language. Nature, 425, 614–616. Ferini-Strambi, L. (2011). Does idiopathic REM sleep behavior disorder (iRBD) really exist? What are the potential markers of neurodegeneration in iRBD [Supplemental material]? Sleep Medicine, 12(2 Suppl.), S43–S49. Fiorentini, A., Volonteri, L.S., Dragogna, F., Rovera, C., Maffini, M., Mauri, M. C., & Altamura, C. A. (2011). Substance-induced psychoses: A critical review of the literature. Current Drug Abuse Reviews, 4, 228–240. Fogel, S. M., & Smith, C. T. (2011). The function of the sleep spindle: A physiological index of intelligence and a mechanism for sleep-dependent memory consolidation. Neuroscience and Biobehavioral Reviews, 35, 1154–1165. Frank, M. G. (2006). The mystery of sleep function: Current perspectives and future directions. Reviews in the Neurosciences, 17, 375–392. Freeman, M. P., Fava, M., Lake, J., Trivedi, M. H., Wisner, K. L., & Mischoulon, D. (2010). Complementary and alternative medicine in major depressive disorder: The American Psychiatric Association task force report. The Journal of Clinical Psychiatry, 71, 669–681. Giedke, H., & Schwärzler, F. (2002). Therapeutic use of sleep deprivation in depression. Sleep Medicine Reviews, 6, 361–377. Gold, D. R., Rogacz, S. R., Bock, N., Tosteson, T. D., Baum, T. M., Speizer, F. M., & Czeisler, C. A. (1992). Rotating shift work, sleep, and accidents related to sleepiness in hospital nurses. American Journal of Public Health, 82, 1011–1014. Golden, W. L. (2012). Cognitive hypnotherapy for anxiety disorders. The American Journal of Clinical Hypnosis, 54, 263–274. Gómez, R. L., Bootzin, R. R., & Nadel, L. (2006). Naps promote abstraction in language-learning infants. Psychological Science, 17, 670–674. Guilleminault, C., Kirisoglu, C., Bao, G., Arias, V., Chan, A., & Li, K. K. (2005). Adult chronic sleepwalking and its treatment based on polysomnography. Brain, 128, 1062–1069. Gujar, N., Yoo, S., Hu, P., & Walker, M. P. (2011). Sleep deprivation amplifies reactivity of brain reward networks, biasing the appraisal of positive emotional experiences. The Journal of Neuroscience, 31, 4466–4474. Guldenmund, P., Vanhaudenhuyse, A., Boly, M., Laureys, S., & Soddu, A. (2012). A default mode of brain function in altered states of consciousness. Archives Italiennes de Biologie, 150, 107–121. Halász, P. (1993). Arousals without awakening—Dynamic aspect of sleep. Physiology and Behavior, 54, 795–802. Han, F. (2012). Sleepiness that cannot be overcome: Narcolepsy and cataplexy. Respirology, 17, 1157–1165. Hardeland, R., Pandi-Perumal, S. R., & Cardinali, D. P. (2006). Melatonin. International Journal of Biochemistry & Cell Biology, 38, 313–316. Haasen, C., & Krausz, M. (2001). Myths versus experience with respect to cocaine and crack: Learning from the US experience. European Addiction Research, 7, 159–160. Henry, D., & Rosenthal, L. (2013). “Listening for his breath:” The significance of gender and partner reporting on the diagnosis, management, and treatment of obstructive sleep apnea. Social Science & Medicine, 79, 48–56. Hicks, R. A., Fernandez, C., & Pelligrini, R. J. (2001). The changing sleep habits of university students: An update. Perceptual and Motor Skills, 93, 648. Hicks, R. A., Johnson, C., & Pelligrini, R. J. (1992). Changes in the self-reported consistency of normal habitual sleep duration of college students (1978 and 1992). Perceptual and Motor Skills, 75, 1168–1170. Hilgard, E. R., & Hilgard, J. R. (1994). Hypnosis in the Relief of Pain. New York: Brunner/Mazel. Hishikawa, Y., & Shimizu, T. (1995). Physiology of REM sleep, cataplexy, and sleep paralysis. Advances in Neurology, 67, 245–271. Herman, A., & Herman, A. P. (2013). Caffeine’s mechanism of action and its cosmetic use. Skin Pharmacology and Physiology, 26, 8–14. Hobson, J. A. (2009). REM sleep and dreaming: Towards a theory of protoconsciousness. Nature Reviews Neuroscience, 10, 803–814. Horikawa,T., Tamaki, M., Miyawaki, Y. & Kamitani, Y. (2013). Neural Decoding of Visual Imagery During Sleep. Science, 340(6132), 639–642. doi:10.1126/science.1234330 Hossain, J. L., & Shapiro, C. M. (2002). The prevalence, cost implications, and management of sleep disorders: An overview. Sleep and Breathing, 6, 85–102. Huang, L. B., Tsai, M. C., Chen, C. Y., & Hsu, S. C. (2013). The effectiveness of light/dark exposure to treat insomnia in female nurses undertaking shift work during the evening/night shift. Journal of Clinical Sleep Medicine, 9, 641–646. Huber, R., Ghilardi, M. F., Massimini, M., & Tononi, G. (2004). Local sleep and learning. Nature, 430, 78–81. Jayanthi, L. D., & Ramamoorthy, S. (2005). Regulation of monoamine transporters: Influence of psychostimulants and therapeutic antidepressants. The AAPS Journal, 7, E728–738. Julien, R. M. (2005). Opioid analgesics. In A primer of drug action: A comprehensive guide to the actions, uses, and side effects of psychoactive drugs (pp. 461–500). Portland, OR: Worth. Kihlstrom, J. F. (2013). Neuro-hypnotism: Prospects for hypnosis and neuroscience. Cortex, 49, 365–374. Klein, D. C., Moore, R. Y., & Reppert, S. M. (Eds.). (1991). Suprachiasmatic nucleus: The mind’s clock. New York, NY: Oxford University Press. Kogan, N. M., & Mechoulam, R. (2007). Cannabinoids in health and disease. Dialogues in Clinical Neuroscience, 9, 413–430. Kromann, C. B., & Nielson, C. T. (2012). A case of cola dependency in a woman with recurrent depression. BMC Research Notes, 5, 692. Lang, A. J., Strauss, J. L., Bomeya, J., Bormann, J. E., Hickman, S. D., Good, R. C., & Essex, M. (2012). The theoretical and empirical basis for meditation as an intervention for PTSD. Behavior Modification, 36, 759–786. LaBerge, S. (1990). Lucid dreaming: Psychophysiological studies of consciousness during REM sleep. In R. R. Bootzen, J. F. Kihlstrom, & D. L. Schacter (Eds.), Sleep and cognition (pp. 109–126). Washington, DC: American Psychological Association. Lesku, J. A., Roth, T. C., 2nd, Amlaner, C. J., & Lima, S. L. (2006). A phylogenetic analysis of sleep architecture in mammals: The integration of anatomy, physiology, and ecology. The American Naturalist, 168, 441–453. Levitt, C., Shaw, E., Wong, S., & Kaczorowski, J. (2007). Systematic review of the literature on postpartum care: Effectiveness of interventions for smoking relapse prevention, cessation, and reduction in postpartum women. Birth, 34, 341–347. Lifshitz, M., Aubert Bonn, N., Fischer, A., Kashem, I. F., & Raz, A. (2013). Using suggestion to modulate automatic processes: From Stroop to McGurk and beyond. Cortex, 49, 463–473. Luppi, P. H., Clément, O., Sapin, E., Gervasoni, D., Peyron, C., Léger, L., . . . Fort, P. (2011). The neuronal network responsible for paradoxical sleep and its dysfunctions causing narcolepsy and rapid eye movement (REM) behavior disorder. Sleep Medicine Reviews, 15, 153–163. Mage, D. T., & Donner, M. (2006). Female resistance to hypoxia: Does it explain the sex difference in mortality rates? Journal of Women’s Health, 15, 786–794. Mahowald, M. W., & Schenck, C. H. (2000). Diagnosis and management of parasomnias. Clinical Cornerstone, 2, 48–54. Mahowald, M. W., Schenck, C. H., & Cramer Bornemann, M. A. (2005). Sleep-related violence. Current Neurology and Neuroscience Reports, 5, 153–158. Mayo Clinic. (n.d.). Sleep terrors (night terrors). Retrieved from http://www.mayoclinic.org/diseases-conditions/ night-terrors/basics/treatment/con-20032552 Mather, L. E., Rauwendaal, E. R., Moxham-Hall, V. L., & Wodak, A. D. (2013). (Re)introducing medical cannabis. The Medical Journal of Australia, 199, 759–761. Maxwell, J. C. (2006). Trends in the abuse of prescription drugs. Gulf Coast Addiction Technology Transfer Center. Retrieved from http://asi.nattc.org/userfiles/file/GulfCoast/PrescriptionTrends_Web McCarty, D. E. (2010). A case of narcolepsy with strictly unilateral cataplexy. Journal of Clinical Sleep Medicine, 15, 75–76. McDaid, C., Durée, K. H., Griffin, S. C., Weatherly, H. L., Stradling, J. R., Davies, R. J., . . . Westwood, M. E. (2009). A systematic review of continuous positive airway pressure for obstructive sleep apnoea-hypopnoea syndrome. Sleep Medicine Reviews, 13, 427–436. McKim, W. A., & Hancock, S. D. (2013). Drugs and behavior: An introduction to behavioral pharmacology, 7th edition. Boston, MA: Pearson. Mignot, E. J. M. (2012). A practical guide to the therapy of narcolepsy and hypersomnia syndromes. Neurotherapeutics, 9, 739–752. Miller, N. L., Shattuck, L. G., & Matsangas, P. (2010). Longitudinal study of sleep patterns of United States Military Academy cadets. Sleep, 33, 1623–1631. Mitchell, E. A. (2009). SIDS: Past, present and future. Acta Paediatrica, 98, 1712–1719. Montgomery, G. H., Schnur, J. B., & Kravits, K. (2012). Hypnosis for cancer care: Over 200 years young. CA: A Cancer Journal for Clinicians, 63, 31–44. National Institutes of Health. (n.d.). Information about sleep. Retrieved from http://science.education.nih.gov/ supplements/nih3/sleep/guide/info-sleep.htm National Research Council. (1994). Learning, remembering, believing: Enhancing human performance. Washington, DC: The National Academies Press. National Sleep Foundation. (n.d.). How much sleep do we really need? Retrieved from http://sleepfoundation.org/ how-sleep-works/how-much-sleep-do-we-really-need Ohayon, M. M. (1997). Prevalence of DSM-IV diagnostic criteria of insomnia: Distinguishing insomnia related to mental disorders from sleep disorders. Journal of Psychiatric Research, 31, 333–346. Ohayon, M. M. (2002). Epidemiology of insomnia: What we know and what we still need to learn. Sleep Medicine Reviews, 6, 97–111. Ohayon, M. M., Carskadon, M. A., Guilleminault, C., & Vitiello, M. V. (2004). Meta-analysis of quantitative sleep parameters from childhood to old age in healthy individuals: Developing normative sleep values across the human lifespan. Sleep, 27, 1255–1273. Ohayon, M. M., & Roth, T. (2002). Prevalence of restless legs syndrome and periodic limb movement disorder in the general population. Journal of Psychosomatic Research, 53, 547–554. Poe, G. R., Walsh, C. M., & Bjorness, T. E. (2010). Cognitive neuroscience of sleep. Progress in Brain Research, 185, 1–19. Porkka-Heiskanen, T. (2011). Methylxanthines and sleep. Handbook of Experimental Pharmacology, 200, 331–348. Presser, H. B. (1995). Job, family, and gender: Determinants of nonstandard work schedules among employed Americans in 1991. Demography, 32, 577–598. Pressman, M. R. (2007). Disorders of arousal from sleep and violent behavior: The role of physical contact and proximity. Sleep, 30, 1039–1047. Provini, F., Tinuper, P., Bisulli, F., & Lagaresi, E. (2011). Arousal disorders [Supplemental material]. Sleep Medicine, 12(2 Suppl.), S22–S26. Rattenborg, N. C., Lesku, J. A., Martinez-Gonzalez, D., & Lima, S. L. (2007). The non-trivial functions of sleep. Sleep Medicine Reviews, 11, 405–409. Raz, A. (2011). Hypnosis: A twilight zone of the top-down variety: Few have never heard of hypnosis but most know little about the potential of this mind-body regulation technique for advancing science. Trends in Cognitive Sciences, 15, 555–557. Raz, A., Shapiro, T., Fan, J., & Posner, M. I. (2002). Hypnotic suggestion and the modulation of Stroop interference. Archives of General Psychiatry, 59, 1151–1161. Reiner, K., Tibi, L., & Lipsitz, J. D. (2013). Do mindfulness-based interventions reduce pain intensity? A critical review of the literature. Pain Medicine, 14, 230–242. Restless Legs Syndrome Foundation. (n.d.). Restless legs syndrome: Causes, diagnosis, and treatment for the patient living with Restless legs syndrome (RSL). Retrieved from www.rls.org Rial, R. V., Nicolau, M. C., Gamundí, A., Akaârir, M., Aparicio, S., Garau, C., . . . Esteban, S. (2007). The trivial function of sleep. Sleep Medicine Reviews, 11, 311–325. Riemann, D., Berger, M., & Volderholzer, U. (2001). Sleep and depression—Results from psychobiological studies: An overview. Biological Psychology, 57, 67–103. Reinerman, C. (2007, October 14). 5 myths about that demon crack. Washington Post. Retrieved from http://www.washingtonpost.com/wp-dyn/content/article/2007/10/09/AR2007100900751.html Reissig, C. J., Strain, E. C., & Griffiths, R. R. (2009). Caffeinated energy drinks—A growing problem. Drug and Alcohol Dependence, 99, 1–10. Robson, P. J. (2014). Therapeutic potential of cannabinoid medicines. Drug Testing and Analysis, 6, 24–30. Roth, T. (2007). Insomnia: Definition, prevalence, etiology, and consequences [Supplemental material]. Journal of Clinical Sleep Medicine, 3(5 Suppl.), S7–S10. Rothman, R. B., Blough, B. E., & Baumann, M. H. (2007). Dual dopamine/serotonin releasers as potential medications for stimulant and alcohol addictions. The AAPS Journal, 9, E1–10. Sánchez-de-la-Torre, M., Campos-Rodriguez, F., & Barbé, F. (2012). Obstructive sleep apnoea and cardiovascular disease. The Lancet Respiratory Medicine, 1, 31–72. Savard, J., Simard, S., Ivers, H., & Morin, C. M. (2005). Randomized study on the efficacy of cognitive-behavioral therapy for insomnia secondary to breast cancer, part I: Sleep and psychological effects. Journal of Clinical Oncology, 23, 6083–6096. Schicho, R., & Storr, M. (2014). Cannabis finds its way into treatment of Crohn’s disease. Pharmacology, 93, 1–3. Shukla, R. K, Crump, J. L., & Chrisco, E. S. (2012). An evolving problem: Methamphetamine production and trafficking in the United States. International Journal of Drug Policy, 23, 426–435. Siegel, J. M. (2008). Do all animals sleep? Trends in Neuroscience, 31, 208–213. Siegel, J. M. (2001). The REM sleep-memory consolidation hypothesis. Science, 294, 1058–1063. Singh, G. K., & Siahpush, M. (2006). Widening socioeconomic inequalities in US life expectancy, 1980–2000. International Journal of Epidemiology, 35, 969–979. Smedslund, G., Fisher, K. J., Boles, S. M., & Lichtenstein, E. (2004). The effectiveness of workplace smoking cessation programmes: A meta-analysis of recent studies. Tobacco Control, 13, 197–204. Sofikitis, N., Giotitsas, N., Tsounapi, P., Baltogiannis, D., Giannakis, D., & Pardalidis, N. (2008). Hormonal regulation of spermatogenesis and spermiogenesis. Journal of Steroid Biochemistry and Molecular Biology, 109, 323–330. Steriade, M., & Amzica, F. (1998). Slow sleep oscillation, rhythmic K-complexes, and their paroxysmal developments [Supplemental material]. Journal of Sleep Research, 7(1 Suppl.), 30–35. Stickgold, R. (2005). Sleep-dependent memory consolidation. Nature, 437, 1272–1278. Stone, K. C., Taylor, D. J., McCrae, C. S., Kalsekar, A., & Lichstein, K. L. (2008). Nonrestorative sleep. Sleep Medicine Reviews, 12, 275–288. Suchecki, D., Tiba, P. A., & Machado, R. B. (2012). REM sleep rebound as an adaptive response to stressful situations. Frontiers in Neuroscience, 3. doi: 10.3389/fneur.2012.00041 Task Force on Sudden Infant Death Syndrome. (2011). SIDS and other sleep-related infant deaths: Expansion of recommendations for a safe infant sleeping environment. Pediatrics, 128, 1030–1039. Taillard, J., Philip, P., Coste, O., Sagaspe, P., & Bioulac, B. (2003). The circadian and homeostatic modulation of sleep pressure during wakefulness differs between morning and evening chronotypes. Journal of Sleep Research, 12, 275–282. Thach, B. T. (2005). The role of respiratory control disorders in SIDS. Respiratory Physiology & Neurobiology, 149, 343–353. U.S. Food and Drug Administration. (2013, October 24). Statement on Proposed Hydrocodone Reclassification from Janet Woodcock, M.D., Director, Center for Drug Evaluation and Research. Retrieved from http://www.fda.gov/drugs/drugsafety/ucm372089.htm Vogel, G. W. (1975). A review of REM sleep deprivation. Archives of General Psychiatry, 32, 749–761. Vøllestad, J., Nielsen, M. B., & Nielsen, G. H. (2012). Mindfulness- and acceptance-based interventions for anxiety disorders: A systematic review and meta-analysis. The British Journal of Clinical Psychology, 51, 239–260. Wagner, U., Gais, S., & Born, J. (2001). Emotional memory formation is enhanced across sleep intervals with high amounts of rapid eye movement sleep. Learning & Memory, 8, 112–119. Wagner, U., Gais, S., Haider, H., Verleger, R., & Born, J. (2004). Sleep improves insight. Nature, 427, 352–355. Walker, M. P. (2009). The role of sleep in cognition and emotion. Annals of the New York Academy of Sciences, 1156, 168–197. Wark, D. M. (2011). Traditional and alert hypnosis for education: A literature review. The American Journal of Clinical Hypnosis, 54(2), 96–106. Waterhouse. J., Fukuda, Y., & Morita, T. (2012). Daily rhythms of the sleep-wake cycle [Special issue]. Journal of Physiological Anthropology, 31(5). doi:10.1186/1880-6805-31-5 Welsh, D. K. Takahashi, J. S., & Kay, S. A. (2010). Suprachiasmatic nucleus: Cell autonomy and network properties. Annual Review of Physiology, 72, 551–577. West, S., Boughton, M., & Byrnes, M. (2009). Juggling multiple temporalities: The shift work story of mid-life nurses. Journal of Nursing Management, 17, 110–119. White, D. P. (2005). Pathogenesis of obstructive and central sleep apnea. American Journal of Respiratory and Critical Care Medicine, 172, 1363–1370. Williams, J., Roth, A., Vatthauer, K., & McCrae, C. S. (2013). Cognitive behavioral treatment of insomnia. Chest, 143, 554–565. Williamson, A. M., & Feyer, A. M. (2000). Moderate sleep deprivation produces impairments in cognitive and motor performance equivalent to legally prescribed levels of alcohol intoxication. Occupational and Environmental Medicine, 57, 649–655. Wolt, B. J., Ganetsky, M., & Babu, K. M. (2012). Toxicity of energy drinks. Current Opinion in Pediatrics, 24, 243–251. Zangini, S., Calandra-Buonaura, G., Grimaldi, D., & Cortelli, P. (2011). REM behaviour disorder and neurodegenerative diseases [Supplemental material]. Sleep Medicine, 12(2 Suppl.), S54–S58. Zeidan, F., Grant, J. A., Brown, C. A., McHaffie, J. G., & Coghill, R. C. (2012). Mindfulness meditation-related pain relief: Evidence for unique brain mechanisms in the regulation of pain. Neuroscience Letters, 520, 165–173. Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Modification, adaptation, and original content. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution CC licensed content, Shared previouslyCC licensed content, Shared previously • Introduction to States of Consciousness. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.48:zywvQOJS@5/Introduction. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/content/col11629/latest/. CONSCIOUSNESS AND BIOLOGICAL RHYTHMS What you’ll learn to do: describe consciousness and biological rhythms Are you tired? Have you ever pulled an all-nighter? How did you feel the next day? Do you think your lack of sleep impacted your behavior? Chances are, you could answer that question with a resounding, “yes!”. Because psychologists are interested in mental processes and behavior, it’s essential to study consciousness, or our awareness, as humans. States of consciousness vary over the course of the day and throughout our lives, and sleep plays a major role in alertness levels. Important factors in daily changes in consciousness are biological rhythms, and, more specifically, the circadian rhythms generated by the suprachiasmatic nucleus. Typically, our biological clocks are aligned with our external environment, and light tends to be an important cue in setting this clock. When people travel across multiple time zones or work rotating shifts, they can experience disruptions of https://creativecommons.org/licenses/by/4.0/ http://cnx.org/contents/Sr8Ev5Og@5.48:zywvQOJS@5/Introduction https://creativecommons.org/licenses/by/4.0/ https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/11/16165526/consciousnessimage their circadian cycles that can lead to insomnia, sleepiness, and decreased alertness. If people go extended periods of time without sleep, they will accrue a sleep debt and potentially experience a number of adverse psychological and physiological consequences. LEARNING OBJECTIVESLEARNING OBJECTIVES • Describe consciousness and circadian rhythms • Explain disruptions in biological rhythms, including sleep debt Consciousness ConsciousnessConsciousness describes our awareness of internal and external stimuli. Awareness of internal stimuli includes feeling pain, hunger, thirst, sleepiness, and being aware of our thoughts and emotions. Awareness of external stimuli includes seeing the light from the sun, feeling the warmth of a room, and hearing the voice of a friend. We experience different states of consciousness and different levels of awareness on a regular basis. We might even describe consciousness as a continuum that ranges from full awareness to a deep sleep. SleepSleep is a state marked by relatively low levels of physical activity and reduced sensory awareness that is distinct from periods of rest that occur during wakefulness. WakefulnessWakefulness is characterized by high levels of sensory awareness, thought, and behavior. In between these extremes are states of consciousness related to daydreaming, intoxication as a result of alcohol or other drug use, meditative states, hypnotic states, and altered states of consciousness following sleep deprivation. We might also experience unconscious states of being via drug-induced anesthesia for medical purposes. Often, we are not completely aware of our surroundings, even when we are fully awake. For instance, have you ever daydreamed while driving home from work or school without really thinking about the drive itself? You were capable of engaging in the all of the complex tasks involved with operating a motor vehicle even though you were not aware of doing so. Many of these processes, like much of psychological behavior, are rooted in our biology. Biological Rhythms Biological rhythmsBiological rhythms are internal rhythms of biological activity. A woman’s menstrual cycle is an example of a biological rhythm—a recurring, cyclical pattern of bodily changes. One complete menstrual cycle takes about 28 days—a lunar month—but many biological cycles are much shorter. For example, body temperature fluctuates cyclically over a 24-hour period (Figure 1). Alertness is associated with higher body temperatures, and sleepiness with lower body temperatures. Figure 1. This chart illustrates the circadian change in body temperature over 28 hours in a group of eight young men. Body temperature rises throughout the waking day, peaking in the afternoon, and falls during sleep with the lowest point occurring during the very early morning hours. This pattern of temperature fluctuation, which repeats every day, is one example of a circadian rhythm. A circadian rhythmcircadian rhythm is a biological rhythm that takes place over a period of about 24 hours. Our sleep-wake cycle, which is linked to our environment’s natural light-dark cycle, is perhaps the most obvious example of a circadian rhythm, but we also have daily fluctuations in heart rate, blood pressure, blood sugar, and body temperature. Some circadian rhythms play a role in changes in our state of consciousness. If we have biological rhythms, then is there some sort of biological clockbiological clock? In the brain, the hypothalamus, which lies above the pituitary gland, is a main center of homeostasis. HomeostasisHomeostasis is the tendency to maintain a balance, or optimal level, within a biological system. The brain’s clock mechanism is located in an area of the hypothalamus known as the suprachiasmatic nucleussuprachiasmatic nucleus (SCN)(SCN). The axons of light-sensitive neurons in the retina provide information to the SCN based on the amount of light present, allowing this internal clock to be synchronized with the outside world (Klein, Moore, & Reppert, 1991; Welsh, Takahashi, & Kay, 2010) (Figure 2). Figure 2. The suprachiasmatic nucleus (SCN) serves as the brain’s clock mechanism. The clock sets itself with light information received through projections from the retina. A YouTube element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2100 LINK TO LEARNINGLINK TO LEARNING Watch this brief video describing circadian rhythms and how they affect sleep. Problems with Circadian Rhythms Generally, and for most people, our circadian cycles are aligned with the outside world. For example, most people sleep during the night and are awake during the day. One important regulator of sleep-wake cycles is the hormone melatoninmelatonin. The pineal glandpineal gland, an endocrine structure located inside the brain that releases melatonin, is thought to be involved in the regulation of various biological rhythms and of the immune system during sleep (Hardeland, Pandi- Perumal, & Cardinali, 2006). Melatonin release is stimulated by darkness and inhibited by light. There are individual differences with regards to our sleep- wake cycle. For instance, some people would say they are morning people, while others would consider themselves to be night owls. These individual differences in circadian patterns of activity are known as a person’s chronotype, and research demonstrates that morning larks and night owls differ with regard to sleep regulation (Taillard, Philip, Coste, Sagaspe, & Bioulac, 2003). Sleep regulationSleep regulation refers to the brain’s control of switching between sleep and wakefulness as well as coordinating this cycle with the outside world. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2100 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2100 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2100 TRY ITTRY IT THINK IT OVERTHINK IT OVER We experience shifts in our circadian clocks in the fall and spring of each year with time changes associated with daylight saving time. Is springing ahead or falling back easier for you to adjust to, and why do you think that is? Disruptions of Normal Sleep Whether lark, owl, or somewhere in between, there are situations in which a person’s circadian clock gets out of synchrony with the external environment. One way that this happens involves traveling across multiple time zones. When we do this, we often experience jet lag. Jet lagJet lag is a collection of symptoms that results from the mismatch between our internal circadian cycles and our environment. These symptoms include fatigue, sluggishness, irritability, and insomniainsomnia (i.e., a consistent difficulty in falling or staying asleep for at least three nights a week over a month’s time) (Roth, 2007). Individuals who do rotating shift work are also likely to experience disruptions in circadian cycles. Rotating shiftRotating shift workwork refers to a work schedule that changes from early to late on a daily or weekly basis. For example, a person may work from 7:00 a.m. to 3:00 p.m. on Monday, 3:00 a.m. to 11:00 a.m. on Tuesday, and 11:00 a.m. to 7:00 p.m. on Wednesday. In such instances, the individual’s schedule changes so frequently that it becomes difficult for a normal circadian rhythm to be maintained. This often results in sleeping problems, and it can lead to signs of depression and anxiety. These kinds of schedules are common for individuals working in health care professions and service industries, and they are associated with persistent feelings of exhaustion and agitation that can make someone more prone to making mistakes on the job (Gold et al., 1992; Presser, 1995). Rotating shift work has pervasive effects on the lives and experiences of individuals engaged in that kind of work, which is clearly illustrated in stories reported in a qualitative study that researched the experiences of middle-aged nurses who worked rotating shifts (West, Boughton & Byrnes, 2009). Several of the nurses interviewed commented that their work schedules affected their relationships with their family. One of the nurses said, If you’ve had a partner who does work regular job 9 to 5 office hours . . . the ability to spend time, good time with them when you’re not feeling absolutely exhausted . . . that would be one of the problems that I’ve encountered. (West et al., 2009, p. 114) While disruptions in circadian rhythms can have negative consequences, there are things we can do to help us realign our biological clocks with the external environment. Some of these approaches, such as using a bright light as shown in Figure 1, have been shown to alleviate some of the problems experienced by individuals Figure 1. Devices like this are designed to provide exposure to bright light to help people maintain a regular circadian cycle. They can be helpful for people working night shifts or for people affected by seasonal variations in light. suffering from jet lag or from the consequences of rotating shift work. Because the biological clock is driven by light, exposure to bright light during working shifts and dark exposure when not working can help combat insomnia and symptoms of anxiety and depression (Huang, Tsai, Chen, & Hsu, 2013). Insufficient Sleep We all NEEDNEED sleep, this we know. What we do not know, however, is WHY we need sleep. See the following for a discussion regarding this: https://youtu.be/EQvhzdVwNMA. When people have difficulty getting sleep due to their work or the demands of day-to-day life, they accumulate a sleep debt. A person with a sleep debtsleep debt does not get sufficient sleep on a chronic basis. The consequences of sleep debt include decreased levels of alertness and mental efficiency. Interestingly, since the advent of electric light, the amount of sleep that people get has declined. While we certainly welcome the convenience of having the darkness lit up, we also suffer the consequences of reduced amounts of sleep because we are more active during the nighttime hours than our ancestors were. As a result, many of us sleep less than 7–8 hours a night and accrue a sleep debt. While there is tremendous variation in any given individual’s sleep needs, the National Sleep Foundation (n.d.) cites research to estimate that newborns require the most sleep (between 12 and 18 hours a night) and that this amount declines to just 7–9 hours by the time we are adults. If you lie down to take a nap and fall asleep very easily, chances are you may have sleep debt. Given that college students are notorious for suffering from significant sleep debt (Hicks, Fernandez, & Pelligrini, 2001; Hicks, Johnson, & Pelligrini, 1992; Miller, Shattuck, & Matsangas, 2010), chances are you and your classmates deal with sleep debt-related issues on a regular basis. The table below shows recommended amounts of sleep at different ages. Sleep Needs at Different Ages AgeAge Nightly Sleep NeedsNightly Sleep Needs 0–3 months 12–18 hours 3 months–1 year 14–15 hours 1–3 years 12–14 hours 3–5 years 11–13 hours 5–10 years 10–11 hours 10–18 years 8–10 hours 18 and older 7–9 hours Sleep debt and sleep deprivation have significant negative psychological and physiological consequences. As mentioned earlier, lack of sleep can result in decreased mental alertness and cognitive function. In addition, sleep deprivation often results in depression-like symptoms. These effects can occur as a function of accumulated sleep debt or in response to more acute periods of sleep deprivation. It may surprise you to know that sleep deprivation is associated with obesity, increased blood pressure, increased levels of stress hormones, and reduced immune functioning (Banks & Dinges, 2007). Furthermore, individuals suffering from sleep deprivation can also put themselves and others at risk when they put themselves behind the wheel of a car or work with dangerous https://youtu.be/EQvhzdVwNMA Figure 2. This figure illustrates some of the negative consequences of sleep deprivation. While cognitive deficits may be the most obvious, many body systems are negatively impacted by lack of sleep. (credit: modification of work by Mikael Häggström) LINK TO LEARNINGLINK TO LEARNING To assess your own sleeping habits, read this article about sleep needs. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2100 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2100 TRY ITTRY IT machinery. Some research suggests that sleep deprivation affects cognitive and motor function as much as, if not more than, alcohol intoxication (Williamson & Feyer, 2000). The amount of sleep we get varies across the lifespan. When we are very young, we spend up to 16 hours a day sleeping. As we grow older, we sleep less. In fact, a meta-analysismeta-analysis, which is a study that combines the results of many related studies, conducted within the last decade indicates that by the time we are 65 years old, we average fewer than 7 hours of sleep per day (Ohayon, Carskadon, Guilleminault, & Vitiello, 2004). As the amount of time we sleep varies over our lifespan, presumably the sleep debt would adjust accordingly. https://sleepfoundation.org/how-sleep-works/how-much-sleep-do-we-really-need An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2100 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2100 GLOSSARYGLOSSARY biological rhythm:biological rhythm: internal cycle of biological activity circadian rhythm:circadian rhythm: biological rhythm that occurs over approximately 24 hours consciousness:consciousness: awareness of internal and external stimuli homeostasis:homeostasis: tendency to maintain a balance, or optimal level, within a biological system insomnia:insomnia: consistent difficulty in falling or staying asleep for at least three nights a week over a month’s time jet lag:jet lag: collection of symptoms brought on by travel from one time zone to another that results from the mismatch between our internal circadian cycles and our environment melatonin:melatonin: hormone secreted by the endocrine gland that serves as an important regulator of the sleep-wake cycle meta-analysis:meta-analysis: study that combines the results of several related studies pineal gland:pineal gland: endocrine structure located inside the brain that releases melatonin rotating shift work:rotating shift work: work schedule that changes from early to late on a daily or weekly basis sleep:sleep: state marked by relatively low levels of physical activity and reduced sensory awareness that is distinct from periods of rest that occur during wakefulness sleep debt:sleep debt: result of insufficient sleep on a chronic basis sleep regulation:sleep regulation: brain’s control of switching between sleep and wakefulness as well as coordinating this cycle with the outside world suprachiasmatic nucleus (SCN):suprachiasmatic nucleus (SCN): area of the hypothalamus in which the body’s biological clock is located wakefulness:wakefulness: characterized by high levels of sensory awareness, thought, and behavior THINK IT OVERTHINK IT OVER What do you do to adjust to the differences in your daily schedule throughout the week? Are you running a sleep debt when daylight saving time begins or ends? LEARNING OBJECTIVESLEARNING OBJECTIVES • Explain blindsight and what it reveals about consciousness If you have already studied about the brain (in the Biopsychology module) then the picture below of the four major lobes of the cerebral cortex should look familiar. Click on the part of the brain that is most heavily involved in vision. https://lumenlearning.h5p.com/content/1290512824128219968/embed https://lumenlearning.h5p.com/content/1290512824128219968/embed Blindsight What do you think would happen if your occipital lobes were damaged? Back in the 1970s, most scientists and physicians would have said, “you would become blind.” It turns out that the answer is more complicated than that. When he was 8-years old, Graham Young from Oxford, England, was injured in a bicycle accident. Afterwards, he reported that parts of his vision were gone. He told his doctors that he could no longer see anything to the right of his center of vision with either his left or right eye. The left side of his visual world in both eyes was normal. Although he says that he would sometimes walk into objects to his right because he couldn’t see them, when tested fifteen years later, an optician discovered that Mr. Young seemed to respond to visual movements in his “blind” area. Figure 1. The illustration shows a top-down view of the neural pathway from the eyes (shown at the top) to the occipital lobes (shown at the bottom). The blue and red lines show the main pathways of information that run from the eyes through the thalamus to the occipital lobes. Because of Graham Young’s damage to his left visual cortex, he cannot see in his right visual field, which affects both eyes. Graham Young was put into contact with Psychologists Larry Weiskrantz and Elizabeth Warrington, who had worked previously with a person (known as DB) who seemed to have a similar ability to see despite blindness. DB could report shapes and colors, movement and the orientation of objects despite claiming that he could see nothing. He said that he was guessing, but he was usually right about colors and shapes and other characteristics of the objects. Before we go on, please take a moment to theorize about what might be going on with Graham Young and DB. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/07/18200627/Screen-Shot-2017-07-18-at-3.05.52-PM https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/07/18200627/Screen-Shot-2017-07-18-at-3.05.52-PM An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2100 TRY ITTRY IT BLINDSIGHT IN ACTIONBLINDSIGHT IN ACTION Here is a brief video of the man who experiences complete blindness because his visual cortex in both hemispheres has been damaged. The researchers (including Dr. Weiskrantz, mentioned above) set up an obstacle course for the man (whose face is blurred to protect his privacy). Watch how well he moves through the objects without help. The man behind him is just there as a safety precaution. https://youtube.com/watch?v=ACkxe_5Ubq8%3Frel%3D0 Figure 2. The green and purple lines represent the primary visual pathway that produces our conscious experience of vision. The red lines roughly represent the secondary pathways that produce visual information with reduced conscious experience, or none at all. (These secondary pathways are not shown precisely). People with blindsight have been tested for their ability to detect color differences, brightness changes, the ability to discriminate between various shapes, as well as tracking movement. Critically, people with blindsight have the conscious experience of blindness, often feeling like they are guessing despite their high level of accuracy. How can blindsight happen? Your conscious experience of the world around you, of the choices and decisions you make, and of the emotions and attitudes that motivate you are not the totality of your mental activity or of your brain’s processing of information. Many, perhaps most, psychologists believe that consciousness is only a small part of your total cognitive activity. (Note: Source: http://marketingland.com/wp-content/ml-loads/2014/09/iceberg-ss-1920 ) A person is considered to be blind if he or she has no conscious experience of the visual world. This conscious experience is based on the flow of information from the eyes through the thalamus in the middle of the brain to the primary visual cortex in the occipital lobe at the back of the brain. If the primary visual cortex is damaged or fails to receive input due to disruption of visual pathway, then the person will not “see” the objects and events that we normally associate with vision. Blindsight occurs because the visual system has a primary pathway (retina to thalamus to primary visual cortex), but it also has secondary pathways (retina to thalamus to other brain areas). These “other brain areas” include parts of the frontal lobe that guide eye movements, parts of the midbrain that help guide visual attention, and parts of the occipital lobe that process features of the visual perception, including shape, movement, and color. (Note: A recent literature review of evidence for the existence of the pathways to the cerebral cortex: Rabbo, F. A., Koch, G., Lefevre, C., & Seizeur, R. (2015). Direct geniculo- extrastriate pathways: A review of the literature. Surgical and Radiologic Anatomy, 37(8), 891-899.) The existence of visual processing areas for isolated features of vision and the fact that these areas get some direct visual information (i.e, input that does not first go to the primary visual cortex) means that it is possible for a person to respond accurately to questions about color or motion or shape without consciously “seeing” the objects that have color or shape or are moving. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/07/13223623/brainimages1 https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/07/13223623/brainimages1 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2100 TRY ITTRY IT EXAMINING BLINDSIGHTEXAMINING BLINDSIGHT You can see Graham Young as he is tested in the lab in this video that shows him along with psychologist Larry Weizkrantz. The video clip (watch just the first 3 minutes), from a program hosted by neurologist V. S. Ramachandran, goes on to explain a theory as to why blindsight occurs. https://youtube.com/watch?v=ny5qMKTcURE%3Fstart%3D01%26end%3D188 It is important to remember that YOU have these same “unconscious” pathways in your visual system. That means your conscious experience of the visual world may not include all of the visual information you are processing. In other words, you may “know” more than you “see”. Blindsight is not the only condition that involves unconscious or low-consciousness processing. Other neurological syndromes that have an unconscious element include amnesia, hemispatial neglect, dyslexia, aphasia, and various agnosias. (Note: See Consciousness Lost and Found: A Neuropsychological Exploration by Larry Weiskrantz (1997, Oxford University Press). Dr. Weiskrantz is one of the scientists who first described blindsight and studied people with the condition.) Creating Blindsight in the Laboratory Wouldn’t it be great if we could produce blindsight in the laboratory, in order to better understand visual processing and conscious experience? Maybe with college student volunteers as our subjects? Crazy idea? Figure 3. Perhaps an unsuspecting student volunteer for transcranial magnetic stimulation. It turns out, researchers have already done it. Using precisely aimed magnetic pulses, researchers can temporarily disrupt specific areas of the primary visual cortex—the area responsible for conscious vision—without injury. This “blindness” lasts only a fraction of a second, after which vision returns to normal. Would you volunteer to be a participant? Let’s look at how this works. TMS: Transcranial Magnetic StimulationTMS: Transcranial Magnetic Stimulation Transcranial magnetic stimulation (TMS) is a procedure used to stimulate neurons in the brain. A device referred to as a “wand” contains an electric coil that generates a magnetic field that in turn creates a small electric current in the brain. (Note: The physics of electromagnetism is fascinating, but we will spare you the details here. You may have studied it in some other class, and there are many readable online sources (e.g., Wikipedia). TMS is a great example of the convergence of technology and psychology that is the basis of modern neuroscience.) The electric current induces neurons (brain cells) to produce neural signals called action potentials. When action potentials are produced in normal brain processes, they allow neurons to communicate with one another. However, when action potentials are induced by an outside force—here by the TMS wand—they are meaningless and temporarily interfere with communication between neurons. If only a single pulse of electromagnetic energy is produced, then the disruption of the neurons in the targeted region lasts only a fraction of a second. Multiple pulses, called repetitive TMS (rTMS), can produce longer lasting effects. In fact, rTMS is now used by therapists as a treatment for depression and neuropathic pain. The TMS pulse can be aimed very precisely at a small area of the brain. When the target is the primary visual cortex in the occipital lobe, the TMS pulse can be focused to interfere with neural communication in a tiny region of the of the visual field—so small and occurring for such a short time that you would not even notice. However brief the duration or tiny the affected area, the person receiving the TMS pulse is temporary blind in a small part of the visual field. Laboratory Research on Unconscious Visual Processing Dr. Tony Ro is a professor of psychology at the City University of New York. He started studying the connection between consciousness and brain processing more than 20 years ago, and he was one of the earliest researchers to apply TMS technology to the study of visual perception. In one study, Dr. Ro and graduate students Jennifer Boyer and Stephenie Harrison used TMS technology to see if normal people could process features of visual stimuli without conscious awareness of those stimuli. In other words, they wanted to know if they could they create temporary blindsight in normal subjects in a laboratory. Remember that blindsight involves unconscious awareness of “features” of objects and events, such as the shape of an object or the direction of its movement. This study focused on two visual features: orientation and color. You and I see orientation (horizontal or vertical) or color (red or green) as part of the experience of some object. A line is horizontal. A box is red. For a person with blindsight, “horizontal” is experienced without any shape associated with it. “Red” is experienced without awareness of the thing that is red. This is the blindsight condition that Dr. Ro and his colleagues wanted to reproduce in the laboratory with the help of volunteer subjects. Let’s walk through the experiment to understand how it was designed and conducted. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/07/14023407/7658074952_5d73170e01_k https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/07/14023407/7658074952_5d73170e01_k An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2100 TRY ITTRY IT Experiment 1: Unconscious Detection of Orientation SETUPSETUP: The TMS wand was precisely adjusted so the TMS pulse was aimed at the back of the brain (primary visual cortex in the occipital lobes) affecting a very small area of the visual field. For example, imagine the gray box below as a computer screen. The plus sign in the middle is a fixation point. You (the participant in the study) fixate your eyes on this plus sign and hold them there during each trial. The TMS pulse is adjusted to your individual brain so that the area shown as a blue circle (used here only for explanation purposes) is momentarily “blind” when the pulse is active. This is a painstaking process that involves fine calibration of the wand based on feedback from the participant about what he or she can see when different targets are shown on the screen. Figure 4. Researchers adjusted the TMS wand until the circle would temporarily disappear from a person’s visual field. TESTINGTESTING: In one of Dr. Ro’s experiments, participants had to guess the orientation of a line, sometimes when they were temporarily blinded (in a tiny area of the visual cortex) by a TMS pulse. The study consisted of a series of trials. On each trial, either a horizontal or a vertical line was flashed for a fraction of a second on the computer screen in front of the participant. On some of these trials, a TMS pulse disrupted the neurons in the visual cortex. On other trials, there was no TMS pulse. The no-pulse trials served as a kind of control condition. Click on the slideshow below to see the steps in the vertical line condition. You can use the arrows at the bottom to navigate through the slides. https://lumenlearning.h5p.com/content/1290512849455705778/embed RESULTSRESULTS: By chance, if you have to choose between two equally likely options (horizontal or vertical), you would be correct about 50% of the time. On the trials when the subjects reported that they did not “see” anything at all, they correctly guessed the orientation of the line 75% of the time, performance that is significantly better than chance. There was also a strong positive correlation (r = +0.93) between accuracy and confidence: the more confident the subject in his or her guess, the more likely it was that the guess was correct. Keep in mind that, in all of these cases, the subjects started by saying that they saw nothing. That was about 60% of the trials. On the other 40% of trials, the subjects reported seeing something, even if it was a slight blur, and these trials did not count. Not surprisingly, accuracy was near perfect when subjects were conscious of seeing the bar and its orientation. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/07/19052107/Screen-Shot-2018-10-19-at-12.20.41-AM https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/07/19052107/Screen-Shot-2018-10-19-at-12.20.41-AM https://lumenlearning.h5p.com/content/1290512849455705778/embed TESTING BLINDSIGHT WITH TMSTESTING BLINDSIGHT WITH TMS Here is a video about a similar experiment conducted by Dr. Ro and his colleagues. The experiment in the video involves detecting yet another feature of objects: their shape. The basic procedures and results are similar to the ones you have just read. https://youtube.com/watch?v=_Y4KsUqmuUw%3Frel%3D0 Variations of the Experiment A second study using the color of a circle rather than the orientation of a bar was reported in the same paper. Otherwise, the procedures were the same as in the first experiment and the results consistent with the results for the bar orientation experiment. Conclusions from the Research The experimenters succeeded in producing the experience of blindness using the TMS apparatus, and they also succeeded in producing evidence for unconscious processing of features of the visual experience in normal (college student) volunteers. These results, when put together with the experiences of people with neurological damage, strengthen the case for the theory that some of our visual perception of the world takes place outside of our awareness. The college students have shown that this unconscious processing is not the result of brain damage, but rather is part of our normal perception of the world. Some Final Words This module has been about consciousness. It is common to assume that everything we know about the world around us and about our own thoughts and internal experiences must go through the doorway of our conscious mind. Evidence from blindsight is just one of several lines of research that shows that we process more information than we are aware of. Learning just how much this unconscious information can influence our thoughts and actions, our preferences and beliefs, is an important challenge for the rising generation of scientists. https://assessments.lumenlearning.com/assessments/4818 Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Modification, adaptation, and original content. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution • Psychology in Real Life: Blindsight. Authored byAuthored by: Patrick Carroll for Lumen Learning. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution CC licensed content, Shared previouslyCC licensed content, Shared previously • What is Consciousness?. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.52:tefy7E6c@6/What-Is-Consciousness. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/contents/4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@5.48 • Authored byAuthored by: Robert Fludd. Provided byProvided by: Wikipedia. Located atLocated at: https://en.wikipedia.org/wiki/Consciousness#/media/File:RobertFuddBewusstsein17Jh . LicenseLicense: Public Domain: No Known Copyright • Reprogramming Our Circadian Rhythms for the Modern World. Authored byAuthored by: Big Think. Located atLocated at: https://www.youtube.com/watch?v=rtCQ9jzC-Ek. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License • Visual pathways image. Provided byProvided by: Wikimedia. Located atLocated at: https://commons.wikimedia.org/wiki/File:Human_visual_pathway.svg. LicenseLicense: CC BY-SA: Attribution-ShareAlike • College student in the park. Authored byAuthored by: CollegeDegrees360. Located atLocated at: https://www.flickr.com/photos/83633410@N07/7658074952. LicenseLicense: CC BY-SA: Attribution-ShareAlike • TN Blindsight. Authored byAuthored by: CANlabTilburg. Located atLocated at: https://www.youtube.com/watch?v=ACkxe_5Ubq8. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License • TMS image. Authored byAuthored by: Losey DM, Stocco A, Abernethy JA and Rao RPN . Located atLocated at: https://www.frontiersin.org/articles/10.3389/frobt.2016.00072/full. ProjectProject: Navigating a 2D Virtual World Using Direct Brain Stimulation.. LicenseLicense: CC BY: Attribution • Image, neuro-ms. Authored byAuthored by: Baburov. Provided byProvided by: Wikimedia. Located atLocated at: https://commons.wikimedia.org/wiki/File:Neuro-ms . LicenseLicense: CC BY-SA: Attribution-ShareAlike All rights reserved contentAll rights reserved content • Seeing Beyond the Visual Cortex - Science Nation. Authored byAuthored by: National Science Foundation. Located atLocated at: https://www.youtube.com/watch?v=_Y4KsUqmuUw. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License • Blindsight experiment - 1989. Authored byAuthored by: Conrad Weiskrantz. Located atLocated at: https://www.youtube.com/watch?time_continue=50&v=wDt_Txi7pC0. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ http://cnx.org/contents/Sr8Ev5Og@5.52:tefy7E6c@6/What-Is-Consciousness https://creativecommons.org/licenses/by/4.0/ https://en.wikipedia.org/wiki/Consciousness#/media/File:RobertFuddBewusstsein17Jh https://creativecommons.org/about/pdm https://www.youtube.com/watch?v=rtCQ9jzC-Ek https://commons.wikimedia.org/wiki/File:Human_visual_pathway.svg https://creativecommons.org/licenses/by-sa/4.0/ https://www.flickr.com/photos/83633410@N07/7658074952 https://creativecommons.org/licenses/by-sa/4.0/ https://www.youtube.com/watch?v=ACkxe_5Ubq8 https://www.frontiersin.org/articles/10.3389/frobt.2016.00072/full https://creativecommons.org/licenses/by/4.0/ https://commons.wikimedia.org/wiki/File:Neuro-ms https://creativecommons.org/licenses/by-sa/4.0/ https://www.youtube.com/watch?v=_Y4KsUqmuUw https://www.youtube.com/watch?time_continue=50&v=wDt_Txi7pC0 PSYCH IN REAL LIFE: CONSCIOUSNESS AND BLINDSIGHT LEARNING OBJECTIVESLEARNING OBJECTIVES • Explain blindsight and what it reveals about consciousness If you have already studied about the brain (in the Biopsychology module) then the picture below of the four major lobes of the cerebral cortex should look familiar. Click on the part of the brain that is most heavily involved in vision. https://lumenlearning.h5p.com/content/1290512824128219968/embed Blindsight What do you think would happen if your occipital lobes were damaged? Back in the 1970s, most scientists and physicians would have said, “you would become blind.” It turns out that the answer is more complicated than that. When he was 8-years old, Graham Young from Oxford, England, was injured in a bicycle accident. Afterwards, he reported that parts of his vision were gone. He told his doctors that he could no longer see anything to the right of his center of vision with either his left or right eye. The left side of his visual world in both eyes was normal. Although he says that he would sometimes walk into objects to his right because he couldn’t see them, when tested fifteen years later, an optician discovered that Mr. Young seemed to respond to visual movements in his “blind” area. https://lumenlearning.h5p.com/content/1290512824128219968/embed TRY ITTRY IT https://assessments.lumenlearning.com/assessments/11394 Figure 1. The illustration shows a top-down view of the neural pathway from the eyes (shown at the top) to the occipital lobes (shown at the bottom). The blue and red lines show the main pathways of information that run from the eyes through the thalamus to the occipital lobes. Because of Graham Young’s damage to his left visual cortex, he cannot see in his right visual field, which affects both eyes. Graham Young was put into contact with Psychologists Larry Weiskrantz and Elizabeth Warrington, who had worked previously with a person (known as DB) who seemed to have a similar ability to see despite blindness. DB could report shapes and colors, movement and the orientation of objects despite claiming that he could see nothing. He said that he was guessing, but he was usually right about colors and shapes and other characteristics of the objects. Before we go on, please take a moment to theorize about what might be going on with Graham Young and DB. People with blindsight have been tested for their ability to detect color differences, brightness changes, the ability to discriminate between various shapes, as well as tracking movement. Critically, people with blindsight have the conscious experience of blindness, often feeling like they are guessing despite their high level of accuracy. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/07/18200627/Screen-Shot-2017-07-18-at-3.05.52-PM https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/07/18200627/Screen-Shot-2017-07-18-at-3.05.52-PM BLINDSIGHT IN ACTIONBLINDSIGHT IN ACTION Here is a brief video of the man who experiences complete blindness because his visual cortex in both hemispheres has been damaged. The researchers (including Dr. Weiskrantz, mentioned above) set up an obstacle course for the man (whose face is blurred to protect his privacy). Watch how well he moves through the objects without help. The man behind him is just there as a safety precaution. https://youtube.com/watch?v=ACkxe_5Ubq8%3Frel%3D0 Figure 2. The green and purple lines represent the primary visual pathway that produces our conscious experience of vision. The red lines roughly represent the secondary pathways that produce visual information with reduced conscious experience, or none at all. (These secondary pathways are not shown precisely). TRY ITTRY IT https://assessments.lumenlearning.com/assessments/11395 How can blindsight happen? Your conscious experience of the world around you, of the choices and decisions you make, and of the emotions and attitudes that motivate you are not the totality of your mental activity or of your brain’s processing of information. Many, perhaps most, psychologists believe that consciousness is only a small part of your total cognitive activity. (Note: Source: http://marketingland.com/wp-content/ml-loads/2014/09/iceberg-ss-1920 ) A person is considered to be blind if he or she has no conscious experience of the visual world. This conscious experience is based on the flow of information from the eyes through the thalamus in the middle of the brain to the primary visual cortex in the occipital lobe at the back of the brain. If the primary visual cortex is damaged or fails to receive input due to disruption of visual pathway, then the person will not “see” the objects and events that we normally associate with vision. Blindsight occurs because the visual system has a primary pathway (retina to thalamus to primary visual cortex), but it also has secondary pathways (retina to thalamus to other brain areas). These “other brain areas” include parts of the frontal lobe that guide eye movements, parts of the midbrain that help guide visual attention, and parts of the occipital lobe that process features of the visual perception, including shape, movement, and color. (Note: A recent literature review of evidence for the existence of the pathways to the cerebral cortex: Rabbo, F. A., Koch, G., Lefevre, C., & Seizeur, R. (2015). Direct geniculo- extrastriate pathways: A review of the literature. Surgical and Radiologic Anatomy, 37(8), 891-899.) The existence of visual processing areas for isolated features of vision and the fact that these areas get some direct visual information (i.e, input that does not first go to the primary visual cortex) means that it is possible for a person to respond accurately to questions about color or motion or shape without consciously “seeing” the objects that have color or shape or are moving. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/07/13223623/brainimages1 https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/07/13223623/brainimages1 EXAMINING BLINDSIGHTEXAMINING BLINDSIGHT You can see Graham Young as he is tested in the lab in this video that shows him along with psychologist Larry Weizkrantz. The video clip (watch just the first 3 minutes), from a program hosted by neurologist V. S. Ramachandran, goes on to explain a theory as to why blindsight occurs. https://youtube.com/watch?v=ny5qMKTcURE%3Fstart%3D01%26end%3D188 Figure 3. Perhaps an unsuspecting student volunteer for transcranial magnetic stimulation. It is important to remember that YOU have these same “unconscious” pathways in your visual system. That means your conscious experience of the visual world may not include all of the visual information you are processing. In other words, you may “know” more than you “see”. Blindsight is not the only condition that involves unconscious or low-consciousness processing. Other neurological syndromes that have an unconscious element include amnesia, hemispatial neglect, dyslexia, aphasia, and various agnosias. (Note: See Consciousness Lost and Found: A Neuropsychological Exploration by Larry Weiskrantz (1997, Oxford University Press). Dr. Weiskrantz is one of the scientists who first described blindsight and studied people with the condition.) Creating Blindsight in the Laboratory Wouldn’t it be great if we could produce blindsight in the laboratory, in order to better understand visual processing and conscious experience? Maybe with college student volunteers as our subjects? Crazy idea? It turns out, researchers have already done it. Using precisely aimed magnetic pulses, researchers can temporarily disrupt specific areas of the primary visual cortex—the area responsible for conscious vision—without injury. This “blindness” lasts only a fraction of a second, after which vision returns to normal. Would you volunteer to be a participant? Let’s look at how this works. TMS: Transcranial Magnetic StimulationTMS: Transcranial Magnetic Stimulation Transcranial magnetic stimulation (TMS) is a procedure used to stimulate neurons in the brain. A device referred to as a “wand” contains an electric coil that generates a magnetic field that in turn creates a small electric current in the brain. (Note: The physics of electromagnetism is fascinating, but we will spare you the details here. You may have studied it in some other class, and there are many readable online sources (e.g., Wikipedia). TMS is a great example of the convergence of technology and psychology that is the basis of modern neuroscience.) The electric current induces neurons (brain cells) to produce neural signals called action potentials. When action potentials are produced in normal brain processes, they allow neurons to communicate with one another. However, when action potentials are induced by an outside force—here by the TMS wand—they are meaningless and temporarily interfere with communication between neurons. If only a single pulse of electromagnetic energy is produced, then the disruption of the neurons in the targeted region lasts only a fraction of a second. Multiple pulses, called repetitive TMS (rTMS), can produce longer lasting effects. In fact, rTMS is now used by therapists as a treatment for depression and neuropathic pain. The TMS pulse can be aimed very precisely at a small area of the brain. When the target is the primary visual cortex in the occipital lobe, the TMS pulse can be focused to interfere with neural communication in a tiny region https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/07/14023407/7658074952_5d73170e01_k https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/07/14023407/7658074952_5d73170e01_k of the of the visual field—so small and occurring for such a short time that you would not even notice. However brief the duration or tiny the affected area, the person receiving the TMS pulse is temporary blind in a small part of the visual field. Laboratory Research on Unconscious Visual Processing Dr. Tony Ro is a professor of psychology at the City University of New York. He started studying the connection between consciousness and brain processing more than 20 years ago, and he was one of the earliest researchers to apply TMS technology to the study of visual perception. In one study, Dr. Ro and graduate students Jennifer Boyer and Stephenie Harrison used TMS technology to see if normal people could process features of visual stimuli without conscious awareness of those stimuli. In other words, they wanted to know if they could they create temporary blindsight in normal subjects in a laboratory. Remember that blindsight involves unconscious awareness of “features” of objects and events, such as the shape of an object or the direction of its movement. This study focused on two visual features: orientation and color. You and I see orientation (horizontal or vertical) or color (red or green) as part of the experience of some object. A line is horizontal. A box is red. For a person with blindsight, “horizontal” is experienced without any shape associated with it. “Red” is experienced without awareness of the thing that is red. This is the blindsight condition that Dr. Ro and his colleagues wanted to reproduce in the laboratory with the help of volunteer subjects. Let’s walk through the experiment to understand how it was designed and conducted. Experiment 1: Unconscious Detection of Orientation SETUPSETUP: The TMS wand was precisely adjusted so the TMS pulse was aimed at the back of the brain (primary visual cortex in the occipital lobes) affecting a very small area of the visual field. For example, imagine the gray box below as a computer screen. The plus sign in the middle is a fixation point. You (the participant in the study) fixate your eyes on this plus sign and hold them there during each trial. The TMS pulse is adjusted to your individual brain so that the area shown as a blue circle (used here only for explanation purposes) is momentarily “blind” when the pulse is active. This is a painstaking process that involves fine calibration of the wand based on feedback from the participant about what he or she can see when different targets are shown on the screen. Figure 4. Researchers adjusted the TMS wand until the circle would temporarily disappear from a person’s visual field. TESTINGTESTING: In one of Dr. Ro’s experiments, participants had to guess the orientation of a line, sometimes when they were temporarily blinded (in a tiny area of the visual cortex) by a TMS pulse. The study consisted of a series of trials. On each trial, either a horizontal or a vertical line was flashed for a fraction of a second on the computer screen in front of the participant. On some of these trials, a TMS pulse disrupted the neurons in the visual cortex. On other trials, there was no TMS pulse. The no-pulse trials served as a kind of control condition. Click on the slideshow below to see the steps in the vertical line condition. You can use the arrows at the bottom to navigate through the slides. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/07/19052107/Screen-Shot-2018-10-19-at-12.20.41-AM https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/07/19052107/Screen-Shot-2018-10-19-at-12.20.41-AM TRY ITTRY IT https://assessments.lumenlearning.com/assessments/11396 TESTING BLINDSIGHT WITH TMSTESTING BLINDSIGHT WITH TMS Here is a video about a similar experiment conducted by Dr. Ro and his colleagues. The experiment in the video involves detecting yet another feature of objects: their shape. The basic procedures and results are similar to the ones you have just read. https://youtube.com/watch?v=_Y4KsUqmuUw%3Frel%3D0 https://lumenlearning.h5p.com/content/1290512849455705778/embed RESULTSRESULTS: By chance, if you have to choose between two equally likely options (horizontal or vertical), you would be correct about 50% of the time. On the trials when the subjects reported that they did not “see” anything at all, they correctly guessed the orientation of the line 75% of the time, performance that is significantly better than chance. There was also a strong positive correlation (r = +0.93) between accuracy and confidence: the more confident the subject in his or her guess, the more likely it was that the guess was correct. Keep in mind that, in all of these cases, the subjects started by saying that they saw nothing. That was about 60% of the trials. On the other 40% of trials, the subjects reported seeing something, even if it was a slight blur, and these trials did not count. Not surprisingly, accuracy was near perfect when subjects were conscious of seeing the bar and its orientation. Variations of the Experiment A second study using the color of a circle rather than the orientation of a bar was reported in the same paper. Otherwise, the procedures were the same as in the first experiment and the results consistent with the results for the bar orientation experiment. Conclusions from the Research The experimenters succeeded in producing the experience of blindness using the TMS apparatus, and they also succeeded in producing evidence for unconscious processing of features of the visual experience in normal (college student) volunteers. These results, when put together with the experiences of people with neurological damage, strengthen the case for the theory that some of our visual perception of the world takes place outside of our awareness. The college students have shown that this unconscious processing is not the result of brain damage, but rather is part of our normal perception of the world. Some Final Words This module has been about consciousness. It is common to assume that everything we know about the world around us and about our own thoughts and internal experiences must go through the doorway of our conscious mind. Evidence from blindsight is just one of several lines of research that shows that we process more information than we are aware of. Learning just how much this unconscious information can influence our thoughts and actions, our preferences and beliefs, is an important challenge for the rising generation of scientists. https://lumenlearning.h5p.com/content/1290512849455705778/embed Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Psychology in Real Life: Blindsight. Authored byAuthored by: Patrick Carroll for Lumen Learning. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution CC licensed content, Shared previouslyCC licensed content, Shared previously • Visual pathways image. Provided byProvided by: Wikimedia. Located atLocated at: https://commons.wikimedia.org/wiki/File:Human_visual_pathway.svg. LicenseLicense: CC BY-SA: Attribution-ShareAlike • College student in the park. Authored byAuthored by: CollegeDegrees360. Located atLocated at: https://www.flickr.com/photos/83633410@N07/7658074952. LicenseLicense: CC BY-SA: Attribution-ShareAlike • TN Blindsight. Authored byAuthored by: CANlabTilburg. Located atLocated at: https://www.youtube.com/watch?v=ACkxe_5Ubq8. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License • TMS image. Authored byAuthored by: Losey DM, Stocco A, Abernethy JA and Rao RPN . Located atLocated at: https://www.frontiersin.org/articles/10.3389/frobt.2016.00072/full. ProjectProject: Navigating a 2D Virtual World Using Direct Brain Stimulation.. LicenseLicense: CC BY: Attribution • Image, neuro-ms. Authored byAuthored by: Baburov. Provided byProvided by: Wikimedia. Located atLocated at: https://commons.wikimedia.org/wiki/File:Neuro-ms . LicenseLicense: CC BY-SA: Attribution-ShareAlike All rights reserved contentAll rights reserved content • Seeing Beyond the Visual Cortex - Science Nation. Authored byAuthored by: National Science Foundation. Located atLocated at: https://www.youtube.com/watch?v=_Y4KsUqmuUw. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License • Blindsight experiment - 1989. Authored byAuthored by: Conrad Weiskrantz. Located atLocated at: https://www.youtube.com/watch?time_continue=50&v=wDt_Txi7pC0. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License SLEEP AND SLEEP STAGES What you’ll learn to do: describe what happens to the brain and body during sleep We devote a very large portion of time to sleep, and our brains have complex systems that control various aspects of sleep. Several hormones important for physical growth and maturation are secreted during sleep. While the reason we sleep remains something of a mystery, there is some evidence to suggest that sleep is very important to learning and memory. You may not feel particularly busy while you sleep, but you’ll learn in this section that your brain and body are quite active. You pass through four different stages of sleep. In this section, you’ll learn more about these sleep stages, dreaming, and sleep disorders. LEARNING OBJECTIVESLEARNING OBJECTIVES • Describe areas of the brain and hormone secretions involved in sleep • Describe several theories (adaptive and cognitive) aimed at explaining the function of sleep https://creativecommons.org/licenses/by/4.0/ https://commons.wikimedia.org/wiki/File:Human_visual_pathway.svg https://creativecommons.org/licenses/by-sa/4.0/ https://www.flickr.com/photos/83633410@N07/7658074952 https://creativecommons.org/licenses/by-sa/4.0/ https://www.youtube.com/watch?v=ACkxe_5Ubq8 https://www.frontiersin.org/articles/10.3389/frobt.2016.00072/full https://creativecommons.org/licenses/by/4.0/ https://commons.wikimedia.org/wiki/File:Neuro-ms https://creativecommons.org/licenses/by-sa/4.0/ https://www.youtube.com/watch?v=_Y4KsUqmuUw https://www.youtube.com/watch?time_continue=50&v=wDt_Txi7pC0 https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/02/08192626/7658254172_091a89cd3b_z • Differentiate between REM and non-REM sleep • Describe the stages of sleep We spend approximately one-third of our lives sleeping. Given the average life expectancy for U.S. citizens falls between 73 and 79 years old (Singh & Siahpush, 2006), we can expect to spend approximately 25 years of our lives sleeping. Some animals never sleep (e.g., several fish and amphibian species); other animals can go extended periods of time without sleep and without apparent negative consequences (e.g., dolphins); yet some animals (e.g., rats) die after two weeks of sleep deprivation (Siegel, 2008). Why do we devote so much time to sleeping? Is it absolutely essential that we sleep? This section will consider these questions and explore various explanations for why we sleep. What is Sleep? You have read that sleep is distinguished by low levels of physical activity and reduced sensory awareness. As discussed by Siegel (2008), a definition of sleep must also include mention of the interplay of the circadian and homeostatic mechanisms that regulate sleep. Homeostatic regulation of sleep is evidenced by sleep rebound following sleep deprivation. Sleep rebound refers to the fact that a sleep-deprived individual will tend to take longer falling asleep during subsequent opportunities for sleep. Sleep is characterized by certain patterns of activity of the brain that can be visualized using electroencephalography (EEG), and different phases of sleep can be differentiated using EEG as well (Figure 1). Sleep-wake cycles seem to be controlled by multiple brain areas acting in conjunction with one another. Some of these areas include the thalamus, the hypothalamus, and the pons. As already mentioned, the hypothalamus contains the SCN—the biological clock of the body—in addition to other nuclei that, in conjunction with the thalamus, regulate slow-wave sleep. The pons is important for regulating rapid eye movement (REM) sleep (National Institutes of Health, n.d.). Sleep is also associated with the secretion and regulation of a number of hormones from several endocrine glands including: melatonin, follicle stimulating hormone (FSH), luteinizing hormone (LH), and growth hormone (National Institutes of Health, n.d.). You have read that the pineal gland releases melatonin during sleep (Figure 2). Melatonin is thought to be involved in the regulation of various biological rhythms and the immune system (Hardeland et al., 2006). During sleep, the pituitary gland secretes both FSH and LH which are important in regulating the reproductive system (Christensen et al., 2012; Sofikitis et al., 2008). The pituitary gland also secretes growth hormone, during sleep, which plays a role in physical growth and maturation as well as other metabolic processes (Bartke, Sun, & Longo, 2013). Figure 1. This is a segment of a polysonograph (PSG), a recording of several physical variables during sleep. The x-axis shows passage of time in seconds; this record includes 30 seconds of data. The location of the sets of electrode that produced each signal is labeled on the y-axis. The red box encompasses EEG output, and the waveforms are characteristic of a specific stage of sleep. Other curves show other sleep-related data, such as body temperature, muscle activity, and heartbeat. Figure 2. The pineal and pituitary glands secrete a number of hormones during sleep. Why Do We Sleep? Given the central role that sleep plays in our lives and the number of adverse consequences that have been associated with sleep deprivation, one would think that we would have a clear understanding of why it is that we sleep. Unfortunately, this is not the case; however, several hypotheses have been proposed to explain the function of sleep. Adaptive Function of Sleep One popular hypothesis of sleep incorporates the perspective of evolutionary psychology. Evolutionary psychology is a discipline that studies how universal patterns of behavior and cognitive processes have evolved over time as a result of natural selection. Variations and adaptations in cognition and behavior make individuals more or less successful in reproducing and passing their genes to their offspring. One hypothesis from this perspective might argue that sleep is essential to restore resources that are expended during the day. Just as bears hibernate in the winter when resources are scarce, perhaps people sleep at night to reduce their energy expenditures. While this is an intuitive explanation of sleep, there is little research that supports this explanation. In fact, it has been suggested that there is no reason to think that energetic demands could not be addressed with periods of rest and inactivity (Frank, 2006; Rial et al., 2007), and some research has actually found a negative correlation between energetic demands and the amount of time spent sleeping (Capellini, Barton, McNamara, Preston, & Nunn, 2008). Another evolutionary hypothesis of sleep holds that our sleep patterns evolved as an adaptive response to predatory risks, which increase in darkness. Thus we sleep in safe areas to reduce the chance of harm. Again, this is an intuitive and appealing explanation for why we sleep. Perhaps our ancestors spent extended periods of time asleep to reduce attention to themselves from potential predators. Comparative research indicates, however, that the relationship that exists between predatory risk and sleep is very complex and equivocal. Some research suggests that species that face higher predatory risks sleep fewer hours than other species (Capellini et al., An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2102 LINK TO LEARNINGLINK TO LEARNING Watch this video to learn more about the function of sleep and the harmful effects of sleep deprivation. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2102 LINK TO LEARNINGLINK TO LEARNING Learn about the connection between memory and sleep in the following clip: TRY ITTRY IT 2008), while other researchers suggest there is no relationship between the amount of time a given species spends in deep sleep and its predation risk (Lesku, Roth, Amlaner, & Lima, 2006). It is quite possible that sleep serves no single universally adaptive function, and different species have evolved different patterns of sleep in response to their unique evolutionary pressures. While we have discussed the negative outcomes associated with sleep deprivation, it should be pointed out that there are many benefits that are associated with adequate amounts of sleep. A few such benefits listed by the National Sleep Foundation (n.d.) include maintaining healthy weight, lowering stress levels, improving mood, and increasing motor coordination, as well as a number of benefits related to cognition and memory formation. Cognitive Function of Sleep Another theory regarding why we sleep involves sleep’s importance for cognitive function and memory formation (Rattenborg, Lesku, Martinez-Gonzalez, & Lima, 2007). Indeed, we know sleep deprivation results in disruptions in cognition and memory deficits (Brown, 2012), leading to impairments in our abilities to maintain attention, make decisions, and recall long-term memories. Moreover, these impairments become more severe as the amount of sleep deprivation increases (Alhola & Polo-Kantola, 2007). Furthermore, slow-wave sleep after learning a new task can improve resultant performance on that task (Huber, Ghilardi, Massimini, & Tononi, 2004) and seems essential for effective memory formation (Stickgold, 2005). Understanding the impact of sleep on cognitive function should help you understand that cramming all night for a test may be not effective and can even prove counterproductive. Sleep has also been associated with other cognitive benefits. Research indicates that included among these possible benefits are increased capacities for creative thinking (Cai, Mednick, Harrison, Kanady, & Mednick, 2009; Wagner, Gais, Haider, Verleger, & Born, 2004), language learning (Fenn, Nusbaum, & Margoliash, 2003; Gómez, Bootzin, & Nadel, 2006), and inferential judgments (Ellenbogen, Hu, Payne, Titone, & Walker, 2007). It is possible that even the processing of emotional information is influenced by certain aspects of sleep (Walker, 2009). An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2102 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2102 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2102 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2102 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2102 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2102 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2102 Visit this course online to take this short practice quiz: Visit this course online to take this short practice quiz: THINK IT OVERTHINK IT OVER Have you (or someone you know) ever experienced significant periods of sleep deprivation because of simple insomnia, high levels of stress, or as a side effect from a medication? What were the consequences of missing out on sleep? Stages of Sleep Sleep is not a uniform state of being. Instead, sleep is composed of several different stages that can be differentiated from one another by the patterns of brain wave activity that occur during each stage. These changes in brain wave activity can be visualized using EEG and are distinguished from one another by both the frequency and amplitude of brain waves (Figure 3). Sleep can be divided into two different general phases: REM sleep and non-REM (NREM) sleep. Rapid eye movement (REM) sleep is characterized by darting movements of the eyes under closed eyelids. Brain waves during REM sleep appear very similar to brain waves during wakefulness. In contrast, non-REM (NREM) sleep is subdivided into three stages distinguished from each other and from wakefulness by characteristic patterns of brain waves. The first three stages of sleep are NREM sleep, while the fourth and final stage of sleep is REM sleep. In this section, we will discuss each of these stages of sleep and their associated patterns of brain wave activity. [Note that psychologists originally identified four stages of non-REM sleep, but these were revised in 2008, resulting in just three distinct phases of NREM sleep. You will see that stage 3 of NREM sleep is sometimes presented as both stage 3 and stage 4 in various texts.] NREM Stages of Sleep The first stage of NREM sleep is known as stage 1 sleep. Stage 1 sleep is a transitional phase that occurs between wakefulness and sleep, the period during which we drift off to sleep. During this time, there is a slowdown in both the rates of respiration and heartbeat. In addition, stage 1 sleep involves a marked decrease in both overall muscle tension and core body temperature. In terms of brain wave activity, stage 1 sleep is associated with both alpha and theta waves. The early portion of stage 1 sleep produces alpha waves, which are relatively low frequency (8–13Hz), high amplitude patterns of electrical activity (waves) that become synchronized (Figure 3). This pattern of brain wave activity resembles that of someone who is very relaxed, yet awake. As an individual continues through stage 1 sleep, there is an increase in theta wave activity. Theta waves are even lower frequency (4–7 Hz), higher amplitude brain waves than alpha waves. It is relatively easy to wake someone from stage 1 sleep; in fact, people often report that they have not been asleep if they are awoken during stage 1 sleep. Figure 3. Brainwave activity changes dramatically across the different stages of sleep. As we move into stage 2 sleep, the body goes into a state of deep relaxation. Theta waves still dominate the activity of the brain, but they are interrupted by brief bursts of activity known as sleep spindles (Figure 4). A sleep spindle is a rapid burst of higher frequency brain waves that may be important for learning and memory (Fogel & Smith, 2011; Poe, Walsh, & Bjorness, 2010). In addition, the appearance of K-complexes is often associated with stage 2 sleep. A K-complex is a very high amplitude pattern of brain activity that may in some cases occur in response to environmental stimuli. Thus, K-complexes might serve as a bridge to higher levels of arousal in response to what is going on in our environments (Halász, 1993; Steriade & Amzica, 1998). https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2015/02/26123807/EEG-Graphic-1 https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2015/02/26123807/EEG-Graphic-1 Figure 4. Stage 2 sleep is characterized by the appearance of both sleep spindles and K-complexes. Stage 3 of sleep is often referred to as deep sleep or slow-wave sleep because these stages are characterized by low frequency (up to 4 Hz), high amplitude delta waves (Figure 5). During this time, an individual’s heart rate and respiration slow dramatically. It is much more difficult to awaken someone from sleep during stage 3 than during earlier stages. Interestingly, individuals who have increased levels of alpha brain wave activity (more often associated with wakefulness and transition into stage 1 sleep) during stage 3 often report that they do not feel refreshed upon waking, regardless of how long they slept (Stone, Taylor, McCrae, Kalsekar, & Lichstein, 2008). An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2102 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2102 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2102 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2102 TRY ITTRY IT Figure 5. Delta waves, which are low frequency and high amplitude, characterize slow-wave stage 3 sleep. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2015/02/26125158/Screen-Shot-2017-04-26-at-7.51.38-AM https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2015/02/26125158/Screen-Shot-2017-04-26-at-7.51.38-AM Figure 6. (a) A period of rapid eye movement is marked by the short red line segment. The brain waves associated with REM sleep, outlined in the red box, look very similar to those seen during wakefulness. REM Sleep As mentioned earlier, REM sleep is marked by rapid movements of the eyes. The brain waves associated with this stage of sleep are very similar to those observed when a person is awake, as shown in Figure 6, and this is the period of sleep in which dreaming occurs. It is also associated with paralysis of muscle systems in the body with the exception of those that make circulation and respiration possible. Therefore, no movement of voluntary muscles occurs during REM sleep in a normal individual; REM sleep is often referred to as paradoxical sleep because of this combination of high brain activity and lack of muscle tone. Like NREM sleep, REM has been implicated in various aspects of learning and memory (Wagner, Gais, & Born, 2001), although there is disagreement within the scientific community about how important both NREM and REM sleep are for normal learning and memory (Siegel, 2001). If people are deprived of REM sleep and then allowed to sleep without disturbance, they will spend more time in REM sleep in what would appear to be an effort to recoup the lost time in REM. This is known as the REM rebound, and it suggests that REM sleep is also homeostatically regulated. Aside from the role that REM sleep may play in processes related to learning and memory, REM sleep may also be involved in emotional processing and regulation. In such instances, REM rebound may actually represent an adaptive response to stress in nondepressed individuals by suppressing the emotional salience of aversive events that occurred in wakefulness (Suchecki, Tiba, & Machado, 2012). While sleep deprivation in general is associated with a number of negative consequences (Brown, 2012), the consequences of REM deprivation appear to be less profound (as discussed in Siegel, 2001). In fact, some have suggested that REM deprivation can actually be beneficial in some circumstances. For instance, REM sleep deprivation has been demonstrated to improve symptoms of people suffering from major depression, and many effective antidepressant medications suppress REM sleep (Riemann, Berger, & Volderholzer, 2001; Vogel, 1975). It should be pointed out that some reviews of the literature challenge this finding, suggesting that sleep deprivation that is not limited to REM sleep is just as effective or more effective at alleviating depressive symptoms among some patients suffering from depression. In either case, why sleep deprivation improves the mood of some patients is not entirely understood (Giedke & Schwärzler, 2002). Recently, however, some have suggested that sleep deprivation might change emotional processing so that various stimuli are more likely to be perceived as positive in nature (Gujar, Yoo, Hu, & Walker, 2011). The hypnogram below (Figure 7) shows a person’s passage through the stages of sleep. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2015/02/26125459/Screen-Shot-2017-04-26-at-7.53.29-AM https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2015/02/26125459/Screen-Shot-2017-04-26-at-7.53.29-AM LINK TO LEARNINGLINK TO LEARNING Read this article that describes the various stages of sleep. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2102 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2102 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2102 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2102 TRY ITTRY IT Figure 7. This hypnogram illustrates how an individual moves through the various stages of sleep. Deeper NREM sleep occurs early on in the night, while the duration of REM sleep increases as the night progresses. https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2015/02/26125708/Sleep-Stages1 https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2015/02/26125708/Sleep-Stages1 https://www.verywell.com/the-four-stages-of-sleep-2795920 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2102 GLOSSARYGLOSSARY alpha wave:alpha wave: type of relatively low frequency, relatively high amplitude brain wave that becomes synchronized; characteristic of the beginning of stage 1 sleep delta wave:delta wave: type of low frequency, high amplitude brain wave characteristic of stage 3 and stage 4 sleep evolutionary psychology:evolutionary psychology: discipline that studies how universal patterns of behavior and cognitive processes have evolved over time as a result of natural selection K-complex:K-complex: very high amplitude pattern of brain activity associated with stage 2 sleep that may occur in response to environmental stimuli non-REM (NREM):non-REM (NREM): period of sleep outside periods of rapid eye movement (REM) sleep rapid eye movement (REM) sleep:rapid eye movement (REM) sleep: period of sleep characterized by brain waves very similar to those during wakefulness and by darting movements of the eyes under closed eyelids sleep rebound:sleep rebound: sleep-deprived individuals will experience longer sleep latencies during subsequent opportunities for sleep sleep spindle:sleep spindle: rapid burst of high frequency brain waves during stage 2 sleep that may be important for learning and memory stage 1 sleep:stage 1 sleep: first stage of sleep; transitional phase that occurs between wakefulness and sleep; the period during which a person drifts off to sleep stage 2 sleep:stage 2 sleep: second stage of sleep; the body goes into deep relaxation; characterized by the appearance of sleep spindles stage 3 sleep:stage 3 sleep: third stage of sleep; deep sleep characterized by low frequency, high amplitude delta waves theta wave:theta wave: type of low frequency, low amplitude brain wave characteristic of the end of stage 1 sleep THINK IT OVERTHINK IT OVER Researchers believe that one important function of sleep is to facilitate learning and memory. How does knowing this help you in your college studies? What changes could you make to your study and sleep habits to maximize your mastery of the material covered in class? Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Modification, adaptation, and original content. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY-SA: Attribution-ShareAlike CC licensed content, Shared previouslyCC licensed content, Shared previously • Sleep and Why We Sleep. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.52:HBTk06bf@7/Sleep-and-Why-We-Sleep. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/contents/4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@5.48 • Image of sleeping girl. Authored byAuthored by: College Degrees 360. Provided byProvided by: Flickr. Located atLocated at: https://www.flickr.com/photos/83633410@N07/7658254172. LicenseLicense: CC BY-SA: Attribution-ShareAlike • What would happen if you didnt sleep? - Claudia Aguirre. Authored byAuthored by: Ted-Ed. Located atLocated at: https://www.youtube.com/watch?v=dqONk48l5vY. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License All rights reserved contentAll rights reserved content • The Connection Between Sleep and Memory . Provided byProvided by: Science360 Video. Located atLocated at: https://science360.gov/obj/video/1bdb1ef6-8a9c-4c06-b8f3-5f6045daf859/connection-between-sleep-memory. LicenseLicense: All Rights Reserved https://creativecommons.org/licenses/by-sa/4.0/ http://cnx.org/contents/Sr8Ev5Og@5.52:HBTk06bf@7/Sleep-and-Why-We-Sleep https://creativecommons.org/licenses/by/4.0/ https://www.flickr.com/photos/83633410@N07/7658254172 https://creativecommons.org/licenses/by-sa/4.0/ https://www.youtube.com/watch?v=dqONk48l5vY https://science360.gov/obj/video/1bdb1ef6-8a9c-4c06-b8f3-5f6045daf859/connection-between-sleep-memory DREAMS AND DREAMING LEARNING OBJECTIVESLEARNING OBJECTIVES • Describe and differentiate between theories on why we dream Dreams The meaning of dreams varies across different cultures and periods of time. By the late 19th century, German psychiatrist Sigmund Freud had become convinced that dreams represented an opportunity to gain access to the unconscious. By analyzing dreams, Freud thought people could increase self-awareness and gain valuable insight to help them deal with the problems they faced in their lives. Freud made distinctions between the manifest content and the latent content of dreams. Manifest contentManifest content is the actual content, or storyline, of a dream. Latent contentLatent content, on the other hand, refers to the hidden meaning of a dream. For instance, if a woman dreams about being chased by a snake, Freud might have argued that this represents the woman’s fear of sexual intimacy, with the snake serving as a symbol of a man’s penis. Freud was not the only theorist to focus on the content of dreams. The 20th century Swiss psychiatrist Carl Jung believed that dreams allowed us to tap into the collective unconsciouscollective unconscious. The collective unconscious, as described by Jung, is a theoretical repository of information he believed to be shared by everyone. According to Jung, certain symbols in dreams reflected universal archetypes with meanings that are similar for all people regardless of culture or location. The sleep and dreaming researcher Rosalind Cartwright, however, believes that dreams simply reflect life events that are important to the dreamer. Unlike Freud and Jung, Cartwright’s ideas about dreaming have found empirical support. For example, she and her colleagues published a study in which women going through divorce were asked several times over a five month period to report the degree to which their former spouses were on their minds. These same women were awakened during REM sleep in order to provide a detailed account of their dream content. There was a significant positive correlation between the degree to which women thought about their former spouses during waking hours and the number of times their former spouses appeared as characters in their dreams (Cartwright, Agargun, Kirkby, & Friedman, 2006). Recent research (Horikawa, Tamaki, Miyawaki, & Kamitani, 2013) has uncovered new techniques by which researchers may effectively detect and classify the visual images that occur during dreaming by using fMRI for neural measurement of brain activity patterns, opening the way for additional research in this area. Recently, neuroscientists have also become interested in understanding why we dream. For example, Hobson (2009) suggests that dreaming may represent a state of protoconsciousness. In other words, dreaming involves constructing a virtual reality in our heads that we might use to help us during wakefulness. Among a variety of neurobiological evidence, John Hobson cites research on lucid dreams as an opportunity to better understand dreaming in general. Lucid dreamsLucid dreams are dreams in which certain aspects of wakefulness are maintained during a dream state. In a lucid dream, a person becomes aware of the fact that they are dreaming, and as such, they can control the dream’s content (LaBerge, 1990). Theories on Dreaming While the Freudian theory of dreaming may be the most well known, and Cartwright’s suggestions on dreaming the most plausible, there are several other theories about the purpose of dreaming. The threat-simulation theorythreat-simulation theory suggests that dreaming should be seen as an ancient biological defense mechanism. Dreams are thought to LINK TO LEARNINGLINK TO LEARNING Review the purpose and stages of sleep as well as the reasons why we dream in the following CrashCourse video: An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2091 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2091 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2091 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2091 TRY ITTRY IT provide an evolutionary advantage because of their capacity to repeatedly simulate potential threatening events. This process enhances the neurocognitive mechanisms required for efficient threat perception and avoidance. The expectation-fulfillment theoryexpectation-fulfillment theory posits that dreaming serves to discharge emotional arousals (however minor) that haven’t been expressed during the day. This practice frees up space in the brain to deal with the emotional arousals of the next day and allows instinctive urges to stay intact. In effect, the expectation is fulfilled (the action is “completed”) in a metaphorical form so that a false memory is not created. This theory explains why dreams are usually forgotten immediately afterwards. One prominent neurobiological theory of dreaming is the activation-synthesis theoryactivation-synthesis theory, which states that dreams don’t actually mean anything. They are merely electrical brain impulses that pull random thoughts and imagery from our memories. The theory posits that humans construct dream stories after they wake up, in a natural attempt to make sense of the nonsensical. However, given the vast documentation of the realistic aspects of human dreaming, as well as indirect experimental evidence that other mammals such as cats also dream, evolutionary psychologists have theorized that dreaming does indeed serve a purpose. The continual-activation theorycontinual-activation theory proposes that dreaming is a result of brain activation and synthesis. Dreaming and REM sleep are simultaneously controlled by different brain mechanisms. The hypothesis states that the function of sleep is to process, encode, and transfer data from short-term memory to long-term memory through a process called consolidation. However, there is not much evidence to back this up. NREM sleep processes the conscious- related memory (declarative memory), and REM sleep processes the unconscious related memory (procedural memory). The underlying assumption of continual-activation theory is that, during REM sleep, the unconscious part of the brain is busy processing procedural memory. Meanwhile, the level of activation in the conscious part of the brain descends to a very low level as the inputs from the senses are basically disconnected. This triggers the “continual-activation” mechanism to generate a data stream from the memory stores to flow through to the conscious part of the brain. A YouTube element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2091 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2091 GLOSSARYGLOSSARY activation-synthesis theory:activation-synthesis theory: states that dreams don’t actually mean anything. Instead, dreams are merely electrical brain impulses that pull random thoughts and imagery from our memories. collective unconscious:collective unconscious: theoretical repository of information shared by all people across cultures, as described by Carl Jung continual-activation theory:continual-activation theory: proposes that dreaming is a result of brain activation and synthesis; its assumption is that, during REM sleep, the unconscious part of the brain is busy processing procedural memory latent content:latent content: hidden meaning of a dream, per Sigmund Freud’s view of the function of dreams lucid dream:lucid dream: people become aware that they are dreaming and can control the dream’s content manifest content:manifest content: storyline of events that occur during a dream, per Sigmund Freud’s view of the function of dreams threat-simulation theory:threat-simulation theory: suggests that dreaming should be seen as an ancient biological defense mechanism that provides an evolutionary advantage because of its capacity to repeatedly simulate potential threatening events, thus enhancing the mechanisms required for efficient threat avoidance. Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Modification, adaptation, and original content. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution CC licensed content, Shared previouslyCC licensed content, Shared previously • Stages of Sleep. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.49:G4i0FY3z@5/Stages-of-Sleep. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/contents/ 4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@5.48 • The Nature and Meaning of Dreams. Provided byProvided by: Boundless. Located atLocated at: https://www.boundless.com/psychology/textbooks/boundless-psychology-textbook/states-of-consciousness-6/sleep-and-dreaming-42/the- nature-and-meaning-of-dreams-184-12719/. LicenseLicense: CC BY-SA: Attribution-ShareAlike All rights reserved contentAll rights reserved content • To Sleep, Perchance to Dream - Crash Course Psychology #9. Provided byProvided by: CrashCourse. Located atLocated at: https://www.youtube.com/watch?v=rMHus-0wFSo. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License SLEEP PROBLEMS AND DISORDERS LEARNING OBJECTIVESLEARNING OBJECTIVES • Describe the symptoms and treatments for insomnia, sleep apnea, and narcolepsy Many people experience disturbances in their sleep at some point in their lives. Depending on the population and sleep disorder being studied, between 30% and 50% of the population suffers from a sleep disorder at some point in their lives (Bixler, Kales, Soldatos, Kaels, & Healey, 1979; Hossain & Shapiro, 2002; Ohayon, 1997, 2002; Ohayon & Roth, 2002). This section will describe several sleep disorders as well as some of their treatment options. Insomnia Insomnia, a consistent difficulty in falling or staying asleep, is the most common of the sleep disorders. Individuals with insomnia often experience long delays between the times that they go to bed and actually fall asleep. In addition, these individuals may wake up several times during the night only to find that they have difficulty getting back to sleep. As mentioned earlier, one of the criteria for insomnia involves experiencing these symptoms for at least three nights a week for at least one month’s time (Roth, 2007). It is not uncommon for people suffering from insomnia to experience increased levels of anxiety about their inability to fall asleep. This becomes a self-perpetuating cycle because increased anxiety leads to increased arousal, and higher levels of arousal make the prospect of falling asleep even more unlikely. Chronic insomnia is almost always associated with feeling overtired and may be associated with symptoms of depression. There may be many factors that contribute to insomnia, including age, drug use, exercise, mental status, and bedtime routines. Not surprisingly, insomnia treatment may take one of several different approaches. People who suffer from insomnia might limit their use of stimulant drugs (such as caffeine) or increase their amount of physical exercise during the day. Some people might turn to over-the-counter (OTC) or prescribed sleep medications to help them sleep, but this should be done sparingly because many sleep medications result in dependence and alter the nature of the sleep cycle, and they can increase insomnia over time. Those who continue to have insomnia, particularly if it affects their quality of life, should seek professional treatment. Some forms of psychotherapy, such as cognitive-behavioral therapycognitive-behavioral therapy, can help sufferers of insomnia. Cognitive- behavioral therapy is a type of psychotherapy that focuses on cognitive processes and problem behaviors. The treatment of insomnia likely would include stress management techniques and changes in problematic behaviors that could contribute to insomnia (e.g., spending more waking time in bed). Cognitive-behavioral therapy has been demonstrated to be quite effective in treating insomnia (Savard, Simard, Ivers, & Morin, 2005; Williams, Roth, Vatthauer, & McCrae, 2013). https://creativecommons.org/licenses/by/4.0/ http://cnx.org/contents/Sr8Ev5Og@5.49:G4i0FY3z@5/Stages-of-Sleep https://creativecommons.org/licenses/by/4.0/ https://www.boundless.com/psychology/textbooks/boundless-psychology-textbook/states-of-consciousness-6/sleep-and-dreaming-42/the-nature-and-meaning-of-dreams-184-12719/ https://www.boundless.com/psychology/textbooks/boundless-psychology-textbook/states-of-consciousness-6/sleep-and-dreaming-42/the-nature-and-meaning-of-dreams-184-12719/ https://creativecommons.org/licenses/by-sa/4.0/ https://www.youtube.com/watch?v=rMHus-0wFSo DIG DEEPER: A SLEEPWALKING DEFENSE?DIG DEEPER: A SLEEPWALKING DEFENSE? On January 16, 1997, Scott Falater sat down to dinner with his wife and children and told them about difficulties he was experiencing on a project at work. After dinner, he prepared some materials to use in leading a church youth group the following morning, and then he attempted repair the family’s swimming pool pump before retiring to bed. The following morning, he awoke to barking dogs and unfamiliar voices from downstairs. As he went to investigate what was going on, he was met by a group of police officers who arrested him for the murder of his wife (Cartwright, 2004; CNN, 1999). Yarmila Falater’s body was found in the family’s pool with 44 stab wounds. A neighbor called the police after witnessing Falater standing over his wife’s body before dragging her into the pool. Upon a search of the premises, police found blood-stained clothes and a bloody knife in the trunk of Falater’s car, and he had blood stains on his neck. Remarkably, Falater insisted that he had no recollection of hurting his wife in any way. His children and his wife’s parents all agreed that Falater had an excellent relationship with his wife and they couldn’t think of a reason that would provide any sort of motive to murder her (Cartwright, 2004). Scott Falater had a history of regular episodes of sleepwalking as a child, and he had even behaved violently toward his sister once when she tried to prevent him from leaving their home in his pajamas during a sleepwalking episode. He suffered from no apparent anatomical brain anomalies or psychological disorders. It appeared that Scott Falater had killed his wife in his sleep, or at least, that is the defense he used when he was tried for his wife’s murder (Cartwright, 2004; CNN, 1999). In Falater’s case, a jury found him guilty of first degree murder in June of 1999 (CNN, 1999); however, there are other murder cases where the sleepwalking defense has been used successfully. As scary as it sounds, many sleep researchers believe that homicidal sleepwalking is possible in individuals suffering from the types of sleep disorders described below (Broughton et al., 1994; Cartwright, 2004; Mahowald, Schenck, & Cramer Bornemann, 2005; Pressman, 2007). Parasomnias A parasomniaparasomnia is one of a group of sleep disorders in which unwanted, disruptive motor activity and/or experiences during sleep play a role. Parasomnias can occur in either REM or NREM phases of sleep. Sleepwalking, restless leg syndrome, and night terrors are all examples of parasomnias (Mahowald & Schenck, 2000). Sleepwalking In sleepwalkingsleepwalking, or somnambulism, the sleeper engages in relatively complex behaviors ranging from wandering about to driving an automobile. During periods of sleepwalking, sleepers often have their eyes open, but they are not responsive to attempts to communicate with them. Sleepwalking most often occurs during slow-wave sleep, but it can occur at any time during a sleep period in some affected individuals (Mahowald & Schenck, 2000). Historically, somnambulism has been treated with a variety of pharmacotherapies ranging from benzodiazepines to antidepressants. However, the success rate of such treatments is questionable. Guilleminault et al. (2005) found that sleepwalking was not alleviated with the use of benzodiazepines. However, all of their somnambulistic patients who also suffered from sleep-related breathing problems showed a marked decrease in sleepwalking when their breathing problems were effectively treated. REM Sleep Behavior Disorder (RBD) REM sleep behavior disorder (RBD)REM sleep behavior disorder (RBD) occurs when the muscle paralysis associated with the REM sleep phase does not occur. Individuals who suffer from RBD have high levels of physical activity during REM sleep, especially during disturbing dreams. These behaviors vary widely, but they can include kicking, punching, scratching, yelling, and behaving like an animal that has been frightened or attacked. People who suffer from this disorder can injure themselves or their sleeping partners when engaging in these behaviors. Furthermore, these types of behaviors ultimately disrupt sleep, although affected individuals have no memories that these behaviors have occurred (Arnulf, 2012). An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=126 TRY ITTRY IT This disorder is associated with a number of neurodegenerative diseases such as Parkinson’s disease. In fact, this relationship is so robust that some view the presence of RBD as a potential aid in the diagnosis and treatment of a number of neurodegenerative diseases (Ferini-Strambi, 2011). Clonazepam, an anti-anxiety medication with sedative properties, is most often used to treat RBD. It is administered alone or in conjunction with doses of melatonin (the hormone secreted by the pineal gland). As part of treatment, the sleeping environment is often modified to make it a safer place for those suffering from RBD (Zangini, Calandra-Buonaura, Grimaldi, & Cortelli, 2011). Other Parasomnias A person with restless leg syndromerestless leg syndrome has uncomfortable sensations in the legs during periods of inactivity or when trying to fall asleep. This discomfort is relieved by deliberately moving the legs, which, not surprisingly, contributes to difficulty in falling or staying asleep. Restless leg syndrome is quite common and has been associated with a number of other medical diagnoses, such as chronic kidney disease and diabetes (Mahowald & Schenck, 2000). There are a variety of drugs that treat restless leg syndrome: benzodiazepines, opiates, and anticonvulsants (Restless Legs Syndrome Foundation, n.d.). Night terrorsNight terrors result in a sense of panic in the sufferer and are often accompanied by screams and attempts to escape from the immediate environment (Mahowald & Schenck, 2000). Although individuals suffering from night terrors appear to be awake, they generally have no memories of the events that occurred, and attempts to console them are ineffective. Typically, individuals suffering from night terrors will fall back asleep again within a short time. Night terrors apparently occur during the NREM phase of sleep (Provini, Tinuper, Bisulli, & Lagaresi, 2011). Generally, treatment for night terrors is unnecessary unless there is some underlying medical or psychological condition that is contributing to the night terrors (Mayo Clinic, n.d.). Sleep Apnea Sleep apneaSleep apnea is defined by episodes during which a sleeper’s breathing stops. These episodes can last 10–20 seconds or longer and often are associated with brief periods of arousal. While individuals suffering from sleep apnea may not be aware of these repeated disruptions in sleep, they do experience increased levels of fatigue. Many individuals diagnosed with sleep apnea first seek treatment because their sleeping partners indicate that they snore loudly and/or stop breathing for extended periods of time while sleeping (Henry & Rosenthal, 2013). Sleep apnea is much more common in overweight people and is often associated with loud snoring. Surprisingly, sleep apnea may exacerbate cardiovascular disease (Sánchez-de-la-Torre, Campos-Rodriguez, & Barbé, 2012). While sleep apnea is less common in thin people, anyone, regardless of their weight, who snores loudly or gasps for air while sleeping, should be checked for sleep apnea. While people are often unaware of their sleep apnea, they are keenly aware of some of the adverse consequences of insufficient sleep. Consider a patient who believed that as a result of his sleep apnea he “had three car accidents in six weeks. They were ALL my fault. Two of them I didn’t even know I was involved in until afterwards” (Henry & Rosenthal, 2013, p. 52). It is not uncommon for people suffering from undiagnosed or untreated sleep apnea to fear that their careers will be affected by the lack of sleep, illustrated by this statement from another patient, “I’m in a job where there’s a premium on being mentally alert. I was really sleepy… and having trouble concentrating…. It was getting to the point where it was kind of scary” (Henry & Rosenthal, 2013, p. 52). There are two types of sleep apnea: obstructive sleep apneaobstructive sleep apnea and central sleep apnea. Obstructive sleep apnea occurs when an individual’s airway becomes blocked during sleep, and air is prevented from entering the lungs. In Figure 1. (a) A typical CPAP device used in the treatment of sleep apnea is (b) affixed to the head with straps, and a mask that covers the nose and mouth. Figure 2. The Safe to Sleep campaign educates the public about how to minimize risk factors associated with SIDS. This campaign is sponsored in part by the National Institute of Child Health and Human Development. central sleep apneacentral sleep apnea, disruption in signals sent from the brain that regulate breathing cause periods of interrupted breathing (White, 2005). One of the most common treatments for sleep apnea involves the use of a special device during sleep. A continuous positive airway pressure (CPAP)continuous positive airway pressure (CPAP) device includes a mask that fits over the sleeper’s nose and mouth, which is connected to a pump that pumps air into the person’s airways, forcing them to remain open, as shown in Figure 1. Some newer CPAP masks are smaller and cover only the nose. This treatment option has proven to be effective for people suffering from mild to severe cases of sleep apnea (McDaid et al., 2009). However, alternative treatment options are being explored because consistent compliance by users of CPAP devices is a problem. Recently, a new EPAP (excitatory positive air pressure) device has shown promise in double-blind trials as one such alternative (Berry, Kryger, & Massie, 2011). SIDS In sudden infant death syndrome (SIDS)sudden infant death syndrome (SIDS) an infant stops breathing during sleep and dies. Infants younger than 12 months appear to be at the highest risk for SIDS, and boys have a greater risk than girls. A number of risk factors have been associated with SIDS including premature birth, smoking within the home, and hyperthermia. There may also be differences in both brain structure and function in infants that die from SIDS (Berkowitz, 2012; Mage & Donner, 2006; Thach, 2005). The substantial amount of research on SIDS has led to a number of recommendations to parents to protect their children (Figure 2). For one, research suggests that infants should be placed on their backs when put down to sleep, and their cribs should not contain any items which pose suffocation threats, such as blankets, pillows or padded crib bumpers (cushions that cover the bars of a crib). Infants should not have caps placed on their heads when put down to sleep in order to prevent overheating, and people in the child’s household should abstain from smoking in the home. Recommendations like these have helped to decrease the number of infant deaths from SIDS in recent years (Mitchell, 2009; Task Force on Sudden Infant Death Syndrome, 2011). An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=126 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=126 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=126 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=126 TRY ITTRY IT Narcolepsy Unlike the other sleep disorders described in this section, a person with narcolepsynarcolepsy cannot resist falling asleep at inopportune times. These sleep episodes are often associated with cataplexycataplexy, which is a lack of muscle tone or muscle weakness, and in some cases involves complete paralysis of the voluntary muscles. This is similar to the kind of paralysis experienced by healthy individuals during REM sleep (Burgess & Scammell, 2012; Hishikawa & Shimizu, 1995; Luppi et al., 2011). Narcoleptic episodes take on other features of REM sleep. For example, around one third of individuals diagnosed with narcolepsy experience vivid, dream-like hallucinations during narcoleptic attacks (Chokroverty, 2010). Surprisingly, narcoleptic episodes are often triggered by states of heightened arousal or stress. The typical episode can last from a minute or two to half an hour. Once awakened from a narcoleptic attack, people report that they feel refreshed (Chokroverty, 2010). Obviously, regular narcoleptic episodes could interfere with the ability to perform one’s job or complete schoolwork, and in some situations, narcolepsy can result in significant harm and injury (e.g., driving a car or operating machinery or other potentially dangerous equipment). Generally, narcolepsy is treated using psychomotor stimulant drugs, such as amphetamines (Mignot, 2012). These drugs promote increased levels of neural activity. Narcolepsy is associated with reduced levels of the signaling molecule hypocretin in some areas of the brain (De la Herrán-Arita & Drucker-Colín, 2012; Han, 2012), and the traditional stimulant drugs do not have direct effects on this system. Therefore, it is quite likely that new medications that are developed to treat narcolepsy will be designed to target the hypocretin system. There is a tremendous amount of variability among sufferers, both in terms of how symptoms of narcolepsy manifest and the effectiveness of currently available treatment options. This is illustrated by McCarty’s (2010) case study of a 50-year-old woman who sought help for the excessive sleepiness during normal waking hours that she had experienced for several years. She indicated that she had fallen asleep at inappropriate or dangerous times, including while eating, while socializing with friends, and while driving her car. During periods of emotional arousal, the woman complained that she felt some weakness in the right side of her body. Although she did not experience any dream-like hallucinations, she was diagnosed with narcolepsy as a result of sleep testing. In her case, the fact that her cataplexy was confined to the right side of her body was quite unusual. Early attempts to treat her condition with a stimulant drug alone were unsuccessful. However, when a stimulant drug was used in conjunction with a popular antidepressant, her condition improved dramatically. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=126 GLOSSARYGLOSSARY cataplexy:cataplexy: lack of muscle tone or muscle weakness, and in some cases complete paralysis of the voluntary muscles central sleep apnea:central sleep apnea: sleep disorder with periods of interrupted breathing due to a disruption in signals sent from the brain that regulate breathing cognitive-behavioral therapy:cognitive-behavioral therapy: psychotherapy that focuses on cognitive processes and problem behaviors that is sometimes used to treat sleep disorders such as insomnia continuous positive airway pressure (CPAP):continuous positive airway pressure (CPAP): device used to treat sleep apnea; includes a mask that fits over the sleeper’s nose and mouth, which is connected to a pump that pumps air into the person’s airways, forcing them to remain open narcolepsy:narcolepsy: sleep disorder in which the sufferer cannot resist falling to sleep at inopportune times night terror:night terror: sleep disorder in which the sleeper experiences a sense of panic and may scream or attempt to escape from the immediate environment obstructive sleep apnea:obstructive sleep apnea: sleep disorder defined by episodes when breathing stops during sleep as a result of blockage of the airway parinsomnia:parinsomnia: one of a group of sleep disorders characterized by unwanted, disruptive motor activity and/or experiences during sleep REM sleep behavior disorder (RBD):REM sleep behavior disorder (RBD): sleep disorder in which the muscle paralysis associated with the REM sleep phase does not occur; sleepers have high levels of physical activity during REM sleep, especially during disturbing dreams restless leg syndrome:restless leg syndrome: sleep disorder in which the sufferer has uncomfortable sensations in the legs when trying to fall asleep that are relieved by moving the legs sleep apnea:sleep apnea: sleep disorder defined by episodes during which breathing stops during sleep sleepwalking:sleepwalking: (also, somnambulism) sleep disorder in which the sleeper engages in relatively complex behaviors sudden infant death syndrome (SIDS):sudden infant death syndrome (SIDS): infant (one year old or younger) with no apparent medical condition suddenly dies during sleep An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=126 THINK IT OVERTHINK IT OVER What factors might contribute to your own experiences with insomnia? Licensing & AttributionsLicensing & Attributions CC licensed content, Shared previouslyCC licensed content, Shared previously • Sleep Problems and Disorders. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.49:Mq2OJ5oK@7/Sleep-Problems-and-Disorders. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/content/col11629/latest/. http://cnx.org/contents/Sr8Ev5Og@5.49:Mq2OJ5oK@7/Sleep-Problems-and-Disorders https://creativecommons.org/licenses/by/4.0/ An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2104 DRUGS AND CONSCIOUSNESS What you’ll learn to do: explain how drugs affect consciousness While we all experience altered states of consciousness in the form of sleep on a regular basis, some people use drugs and other substances that result in altered states of consciousness as well. This section will present information relating to the use of various psychoactive drugs and problems associated with such use. You’ll also learned about other altered states of consciousness like hypnosis and meditation. This CrashCourse video gives an excellent overview of these altered states: LEARNING OBJECTIVESLEARNING OBJECTIVES • Describe how substance abuse disorders are diagnosed • Explain how depressants impact nervous system activity • Identify stimulants and describe how they affect the brain and body • Identify opioids and describe how they impact the brain and behavior • Describe hallucinogens and how they affect the brain and behavior • Compare and contrast between depressants, stimulants, opioids, and hallucinogens Substance Abuse Disorders The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders,, Fifth Edition (DSM-5)(DSM-5) is used by clinicians to diagnose individuals suffering from various psychological disorders. Drug use disorders are addictive disorders, and the criteria for specific substance (drug) use disorders are described in DSM-5. A person https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/02/14223552/800px-Mandelbrot_Islands_of_Consciousness LINK TO LEARNINGLINK TO LEARNING Read through this fascinating comic created by Stuart McMillen about psychologist’s Bruce Alexander’s Rat Park study on addiction, found here. For more information on Bruce Alexander’s study and a better understanding of addiction, listen to Johann Hari’s TED Talk, “Everything you think you know about addiction is wrong.” who has a substance use disorder often uses more of the substance than they originally intended to and continues to use that substance despite experiencing significant adverse consequences. In individuals diagnosed with a substance use disorder, there is a compulsive pattern of drug use that is often associated with both physical and psychological dependence. Physical dependencePhysical dependence involves changes in normal bodily functions—the user will experience withdrawal from the drug upon cessation of use. In contrast, a person who has psychological dependencepsychological dependence has an emotional, rather than physical, need for the drug and may use the drug to relieve psychological distress. ToleranceTolerance is linked to physiological dependence, and it occurs when a person requires more and more drug to achieve effects previously experienced at lower doses. Tolerance can cause the user to increase the amount of drug used to a dangerous level—even to the point of overdose and death. Drug withdrawalwithdrawal includes a variety of negative symptoms experienced when drug use is discontinued. These symptoms usually are opposite of the effects of the drug. For example, withdrawal from sedative drugs often produces unpleasant arousal and agitation. In addition to withdrawal, many individuals who are diagnosed with substance use disorders will also develop tolerance to these substances. Psychological dependence, or drug craving, is a recent addition to the diagnostic criteria for substance use disorder in DSM-5. This is an important factor because we can develop tolerance and experience withdrawal from any number of drugs that we do not abuse. In other words, physical dependence in and of itself is of limited utility in determining whether or not someone has a substance use disorder. Drug Categories The effects of all psychoactive drugs occur through their interactions with our endogenous neurotransmitter systems. Many of these drugs, and their relationships, are shown in Figure 1. As you have learned, drugs can act as agonists or antagonists of a given neurotransmitter system. An agonist facilitates the activity of a neurotransmitter system, and antagonists impede neurotransmitter activity. The main categories of drugs are depressantsdepressants, stimulantsstimulants, and hallucinogenshallucinogens. You’ll learn more about these types drugs in the coming pages. http://www.stuartmcmillen.com/comics_en/rat-park/ https://www.ted.com/talks/johann_hari_everything_you_think_you_know_about_addiction_is_wrong Figure 1. This figure illustrates various drug categories and overlap among them. (credit: modification of work by Derrick Snider) An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2104 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2104 TRY ITTRY IT Depressants Ethanol, which we commonly refer to as alcohol, is in a class of psychoactive drugs known as depressants (Figure 1). A depressantdepressant is a drug that tends to suppress central nervous system activity. Other depressants include barbiturates and benzodiazepines. These drugs share in common their ability to serve as agonists of the gamma-Aminobutyric acid (GABA) neurotransmitter system. Because GABA has a quieting effect on the brain, GABA agonists also have a quieting effect; these types of drugs are often prescribed to treat both anxiety and insomnia. Figure 2. The GABA-gated chloride (Cl-) channel is embedded in the cell membrane of certain neurons. The channel has multiple receptor sites where alcohol, barbiturates, and benzodiazepines bind to exert their effects. The binding of these molecules opens the chloride channel, allowing negatively-charged chloride ions (Cl-) into the neuron’s cell body. Changing its charge in a negative direction pushes the neuron away from firing; thus, activating a GABA neuron has a quieting effect on the brain. Acute alcohol administration results in a variety of changes to consciousness. At rather low doses, alcohol use is associated with feelings of euphoria. As the dose increases, people report feeling sedated. Generally, alcohol is associated with decreases in reaction time and visual acuity, lowered levels of alertness, and reduction in behavioral control. With excessive alcohol use, a person might experience a complete loss of consciousness and/ or difficulty remembering events that occurred during a period of intoxication (McKim & Hancock, 2013). In addition, if a pregnant woman consumes alcohol, her infant may be born with a cluster of birth defects and symptoms collectively called fetal alcohol spectrum disorder (FASD) or fetal alcohol syndrome (FAS). With repeated use of many central nervous system depressants, such as alcohol, a person becomes physically dependent upon the substance and will exhibit signs of both tolerance and withdrawal. Psychological dependence An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2104 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2104 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2104 TRY ITTRY IT on these drugs is also possible. Therefore, the abuse potential of central nervous system depressants is relatively high. Drug withdrawal is usually an aversive experience, and it can be a life-threatening process in individuals who have a long history of very high doses of alcohol and/or barbiturates. This is of such concern that people who are trying to overcome addiction to these substances should only do so under medical supervision. Stimulants StimulantsStimulants are drugs that tend to increase overall levels of neural activity. Many of these drugs act as agonists of the dopamine neurotransmitter system. Dopamine activity is often associated with reward and craving; therefore, drugs that affect dopamine neurotransmission often have abuse liability. Drugs in this category include cocaine, amphetamines (including methamphetamine), cathinones (i.e., bath salts), MDMA (ecstasy), nicotine, and caffeine. Cocaine can be taken in multiple ways. While many users snort cocaine, intravenous injection and ingestion are also common. The freebase version of cocaine, known as crack, is a potent, smokable version of the drug. Like many other stimulants, cocaine agonizes the dopamine neurotransmitter system by blocking the reuptake of dopamine in the neuronal synapse. Figure 3. Crack rocks like these are smoked to achieve a high. Compared with other routes of administration, smoking a drug allows it to enter the brain more rapidly, which can often enhance the user’s experience. (credit: modification of work by U.S. Department of Justice) DIG DEEPER: CRACK COCAINEDIG DEEPER: CRACK COCAINE Crack (Figure 3) is often considered to be more addictive than cocaine itself because it is smokable and reaches the brain very quickly. Crack is often less expensive than other forms of cocaine; therefore, it tends to be a more accessible drug for individuals from impoverished segments of society. During the 1980s, many drug laws were rewritten to punish crack users more severely than cocaine users. This led to discriminatory sentencing with low-income, inner-city minority populations receiving the harshest punishments. The wisdom of these laws has recently been called into question, especially given research that suggests crack may not be more addictive than other forms of cocaine, as previously thought (Haasen & Krausz, 2001; Reinerman, 2007). Figure 4. As one of their mechanisms of action, cocaine and amphetamines block the reuptake of dopamine from the synapse into the presynaptic cell. Amphetamines have a mechanism of action quite similar to cocaine in that they block the reuptake of dopamine in addition to stimulating its release (Figure 4). While amphetamines are often abused, they are also commonly prescribed to children diagnosed with attention deficit hyperactivity disorder (ADHD). It may seem counterintuitive that stimulant medications are prescribed to treat a disorder that involves hyperactivity, but the therapeutic effect comes from increases in neurotransmitter activity within certain areas of the brain associated with impulse control. In recent years, methamphetamine (meth) use has become increasingly widespread. MethamphetamineMethamphetamine is a type of amphetamine that can be made from ingredients that are readily available (e.g., medications containing pseudoephedrine, a compound found in many over-the- counter cold and flu remedies). Despite recent changes in laws designed to make obtaining pseudoephedrine more difficult, methamphetamine continues to be an easily accessible and relatively inexpensive drug option (Shukla, Crump, & Chrisco, 2012). The cocaine, amphetamine, cathinones, and MDMA users seek a euphoric higheuphoric high, feelings of intense elation and pleasure, especially in those users who take the drug via intravenous injection or smoking. Repeated use of these stimulants can have significant adverse consequences. Users can experience physical symptoms that include nausea, elevated blood pressure, and increased heart rate. In addition, these drugs can cause feelings of anxiety, hallucinations, and paranoia (Fiorentini et al., 2011). Normal brain functioning is altered after repeated use of these drugs. For example, repeated use can lead to overall depletion among the monoamine neurotransmitters (dopamine, norepinephrine, and serotonin). People may engage in compulsive use of these stimulant substances in part to try to reestablish normal levels of these neurotransmitters (Jayanthi & Ramamoorthy, 2005; Rothman, Blough, & Baumann, 2007). CaffeineCaffeine is another stimulant drug. While it is probably the most commonly used drug in the world, the potency of this particular drug pales in comparison to the other stimulant drugs described in this section. Generally, people use caffeine to maintain increased levels of alertness and arousal. Caffeine is found in many common medicines (such as weight loss drugs), beverages, foods, and even cosmetics (Herman & Herman, 2013). While caffeine may have some indirect effects on dopamine neurotransmission, its primary mechanism of action involves antagonizing adenosine activity (Porkka-Heiskanen, 2011). While caffeine is generally considered a relatively safe drug, high blood levels of caffeine can result in insomnia, agitation, muscle twitching, nausea, irregular heartbeat, and even death (Reissig, Strain, & Griffiths, 2009; Wolt, Ganetsky, & Babu, 2012). In 2012, Kromann and Nielson reported on a case study of a 40-year-old woman who suffered significant ill effects from her use of caffeine. The woman used caffeine in the past to boost her mood and to provide energy, but over the course of several years, she increased her caffeine consumption to the point that she was consuming three liters of soda each day. Although she had been taking a prescription antidepressant, her symptoms of depression continued to worsen and she began to suffer physically, displaying significant warning signs of cardiovascular disease and diabetes. Upon admission to an outpatient clinic for treatment of mood disorders, she met all of the diagnostic criteria for substance dependence and was advised to dramatically limit her caffeine intake. Once she was able to limit her use to less than 12 ounces of soda a day, both her mental and physical health gradually improved. Despite the prevalence of caffeine use and the large number of people who confess to suffering from caffeine addiction, this was the first published description of soda dependence appearing in scientific literature. Nicotine is highly addictive, and the use of tobacco products is associated with increased risks of heart disease, stroke, and a variety of cancers. Nicotine exerts its effects through its interaction with acetylcholine receptors. Acetylcholine functions as a neurotransmitter in motor neurons. In the central nervous system, it plays a role in arousal and reward mechanisms. Nicotine is most commonly used in the form of tobacco products like cigarettes or chewing tobacco; therefore, there is a tremendous interest in developing effective smoking cessation techniques. To date, people have used a variety of nicotine replacement therapies in addition to various psychotherapeutic options in an attempt to discontinue their use of tobacco products. In general, smoking cessation programs may be effective in the short term, but it is unclear whether these effects persist (Cropley, LINK TO LEARNINGLINK TO LEARNING To learn more about some of the most commonly abused prescription and street drugs, check out the Commonly Abused Drugs Chart and the Commonly Abused Prescription Drugs Chart from the National Institute on Drug Abuse. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2104 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2104 TRY ITTRY IT Theadom, Pravettoni, & Webb, 2008; Levitt, Shaw, Wong, & Kaczorowski, 2007; Smedslund, Fisher, Boles, & Lichtenstein, 2004). Opioids An opioidopioid is one of a category of drugs that includes heroin, morphine, methadone, and codeine. Opioids have analgesic properties; that is, they decrease pain. Humans have an endogenous opioid neurotransmitter system—the body makes small quantities of opioid compounds that bind to opioid receptors reducing pain and producing euphoria. Thus, opioid drugs, which mimic this endogenous painkilling mechanism, have an extremely high potential for abuse. Natural opioids, called opiates, are derivatives of opium, which is a naturally occurring compound found in the poppy plant. There are now several synthetic versions of opiate drugs (correctly called opioids) that have very potent painkilling effects, and they are often abused. For example, the National Institutes of Drug Abuse has sponsored research that suggests the misuse and abuse of the prescription pain killers hydrocodone and oxycodone are significant public health concerns (Maxwell, 2006). In 2013, the U.S. Food and Drug Administration recommended tighter controls on their medical use. Historically, heroin has been a major opioid drug of abuse (Figure 5). Heroin can be snorted, smoked, or injected intravenously. Like the stimulants described earlier, the use of heroin is associated with an initial feeling of euphoria followed by periods of agitation. Because heroin is often administered via intravenous injection, users often bear needle track marks on their arms and, like all abusers of intravenous drugs, have an increased risk for contraction of both tuberculosis and HIV. https://www.drugabuse.gov/drugs-abuse/commonly-abused-drugs-charts https://www.drugabuse.gov/drugs-abuse/commonly-abused-drugs-charts Figure 5. (a) Common paraphernalia for heroin preparation and use are shown here in a needle exchange kit. (b) Heroin is cooked on a spoon over a candle. (credit a: modification of work by Todd Huffman) An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2104 TRY ITTRY IT Aside from their utility as analgesic drugs, opioid-like compounds are often found in cough suppressants, anti- nausea, and anti-diarrhea medications. Given that withdrawal from a drug often involves an experience opposite to the effect of the drug, it should be no surprise that opioid withdrawal resembles a severe case of the flu. While opioid withdrawal can be extremely unpleasant, it is not life-threatening (Julien, 2005). Still, people experiencing opioid withdrawal may be given methadonemethadone to make withdrawal from the drug less difficult. Methadone is a synthetic opioid that is less euphorigenic than heroin and similar drugs. Methadone clinicsMethadone clinics help people who previously struggled with opioid addiction manage withdrawal symptoms through the use of methadone. Other drugs, including the opioid buprenorphine, have also been used to alleviate symptoms of opiate withdrawal. CodeineCodeine is an opioid with relatively low potency. It is often prescribed for minor pain, and it is available over-the- counter in some other countries. Like all opioids, codeine does have abuse potential. In fact, abuse of prescription opioid medications is becoming a major concern worldwide (Aquina, Marques-Baptista, Bridgeman, & Merlin, 2009; Casati, Sedefov, & Pfeiffer-Gerschel, 2012). Figure 6. Psychedelic images like this are often associated with hallucinogenic compounds. (credit: modification of work by “new 1lluminati”/Flickr) Figure 7. Medical marijuana shops are becoming more and more common in the United States. (credit: Laurie Avocado) DIG DEEPER: MEDICAL MARIJUANADIG DEEPER: MEDICAL MARIJUANA While the possession and use of marijuana is illegal in most states, it is now legal in Washington, Colorado, Oregon, and Alaska to possess limited quantities of marijuana for recreational use. In contrast, medical marijuana use is now legal in nearly half of the United States. Medical marijuana is marijuana that is prescribed by a doctor for the treatment of a health condition. For example, people who undergo chemotherapy will often be prescribed marijuana to stimulate their appetites and prevent excessive weight loss resulting from the side effects of chemotherapy treatment. Marijuana may also have some promise in the treatment of a variety of medical conditions (Mather, Rauwendaal, Moxham-Hall, & Wodak, 2013; Robson, 2014; Schicho & Storr, 2014). While medical marijuana laws have been passed on a state-by-state basis, federal laws still classify this as an illicit substance, making conducting research on the potentially beneficial medicinal uses of marijuana problematic. There is quite a bit of controversy within the scientific community as to the extent to which marijuana might have medicinal benefits due to a lack of large- scale, controlled research (Bostwick, 2012). As a result, many scientists have urged the federal government to allow for relaxation of current marijuana laws and classifications in order to facilitate a more widespread study of the drug’s effects (Aggarwal et al., 2009; Bostwick, 2012; Kogan & Mechoulam, 2007). Until recently, the United States Department of Justice routinely arrested people involved and seized marijuana used in medicinal settings. In the latter part of 2013, however, the United States Department of Justice issued statements indicating that they would not continue to challenge state medical marijuana laws. This shift in policy may be in response to the scientific community’s recommendations and/or reflect changing public opinion regarding marijuana. TRY ITTRY IT Hallucinogens A hallucinogenhallucinogen is one of a class of drugs that results in profound alterations in sensory and perceptual experiences (Figure 6). In some cases, users experience vivid visual hallucinations. Common hallucinogens include marijuana, psilocybin (shrooms), mescaline (peyote), and LSD. It is also common for these types of drugs to cause hallucinations of body sensations (e.g., feeling as if you are a giant) and a skewed perception of the passage of time. As a group, hallucinogens are incredibly varied in terms of the neurotransmitter systems they affect. Mescaline and LSD are serotonin agonists, and PCP (angel dust) and ketamine (an animal anesthetic) act as antagonists of the NMDA glutamate receptor. In general, these drugs are not thought to possess the same sort of abuse potential as other classes of drugs discussed in this section. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2104 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2104 LINK TO LEARNINGLINK TO LEARNING Practice your understanding of how drugs affect neurotransmitters in the brain in the the PsychSim Tutorial “Your Mind on Drugs.” The tutorial is only intended for practice. Please disregard the final screen that requests you submit answers to your instructor. Then visit the Mouse Party website to see a visual example of how drugs alter the chemicals in the brain. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2104 TRY ITTRY IT GLOSSARYGLOSSARY codeine:codeine: opiate with relatively low potency often prescribed for minor pain depressant:depressant: drug that tends to suppress central nervous system activity euphoric high:euphoric high: feelings of intense elation and pleasure from drug use hallucinogen:hallucinogen: one of a class of drugs that results in profound alterations in sensory and perceptual experiences, often with vivid hallucinations methadone:methadone: synthetic opioid that is less euphorogenic than heroin and similar drugs; used to manage withdrawal symptoms in opiate users methadone clinic:methadone clinic: uses methadone to treat withdrawal symptoms in opiate users Summary of Psychoactive Drugs Substance use disorder is defined in DSM-5 as a compulsive pattern of drug use despite negative consequences. Both physical and psychological dependence are important parts of this disorder. Alcohol, barbiturates, and benzodiazepines are central nervous system depressants that affect GABA neurotransmission. Cocaine, amphetamine, cathinones, and MDMA are all central nervous stimulants that agonize dopamine neurotransmission, while nicotine and caffeine affect acetylcholine and adenosine, respectively. Opiate drugs serve as powerful analgesics through their effects on the endogenous opioid neurotransmitter system, and hallucinogenic drugs cause pronounced changes in sensory and perceptual experiences. The hallucinogens are variable with regards to the specific neurotransmitter systems they affect. http://bcs.worthpublishers.com/webpub/Ektron/Myers_Psychology%2010e/PsychSim5_Tutorials/Your_Mind_On_Drugs/your_mind_on_drugs.htm http://learn.genetics.utah.edu/content/addiction/mouse/ methamphetamine:methamphetamine: type of amphetamine that can be made from pseudoephedrine, an over-the-counter drug; widely manufactured and abusedopiate/opioid:opiate/opioid: one of a category of drugs that has strong analgesic properties; opiates are produced from the resin of the opium poppy; includes heroin, morphine, methadone, and codeine opiate/opioid:opiate/opioid: one of a category of drugs that has strong analgesic properties; opiates are produced from the resin of the opium poppy; includes heroin, morphine, methadone, and codeine physical dependence:physical dependence: changes in normal bodily functions that cause a drug user to experience withdrawal symptoms upon cessation of use psychological dependence:psychological dependence: emotional, rather than a physical, need for a drug which may be used to relieve psychological distress stimulant:stimulant: drug that tends to increase overall levels of neural activity; includes caffeine, nicotine, amphetamines, and cocaine tolerance:tolerance: state of requiring increasing quantities of the drug to gain the desired effect withdrawal:withdrawal: variety of negative symptoms experienced when drug use is discontinued Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Modification, adaptation, and original content. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution CC licensed content, Shared previouslyCC licensed content, Shared previously • Psychology. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.52:fOU1RGxh@6/Substance-Use-and-Abuse. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/ contents/4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@5.48 • Mandelbrot Islands of Consciousness image. Authored byAuthored by: David R. Ingham. Provided byProvided by: Wikipedia. Located atLocated at: https://commons.wikimedia.org/wiki/File:Mandelbrot_Islands_of_Consciousness . LicenseLicense: CC BY-SA: Attribution-ShareAlike • LicenseLicense: Public Domain: No Known Copyright All rights reserved contentAll rights reserved content • Altered States - Crash Course Psychology #10. Provided byProvided by: CrashCourse. Located atLocated at: https://youtu.be/9PW1fwKjo-Y?list=PL8dPuuaLjXtOPRKzVLY0jJY-uHOH9KVU6. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License HYPNOSIS AND MEDITATION LEARNING OBJECTIVESLEARNING OBJECTIVES • Describe hypnosis and meditation Our states of consciousness change as we move from wakefulness to sleep. We also alter our consciousness through the use of various psychoactive drugs. This final section will consider hypnotic and meditative states as additional examples of altered states of consciousness experienced by some individuals. Hypnosis HypnosisHypnosis is a state of extreme self-focus and attention in which minimal attention is given to external stimuli. In the therapeutic setting, a clinician often will use relaxation and suggestion in an attempt to alter the thoughts and perceptions of a patient. Hypnosis has also been used to draw out information believed to be buried deeply in someone’s memory. For individuals who are especially open to the power of suggestion, this can prove to be a very effective technique, and brain imaging studies have demonstrated that hypnotic states are associated with global changes in brain functioning (Del Casale et al., 2012; Guldenmund, Vanhaudenhuyse, Boly, Laureys, & Soddu, 2012). Historically, hypnosis has been viewed with some suspicion because of its portrayal in popular media and entertainment (Figure 1). Therefore, it is important to make a distinction between hypnosis as an empirically based therapeutic approach versus as a form of entertainment. Contrary to popular belief, individuals undergoing https://creativecommons.org/licenses/by/4.0/ http://cnx.org/contents/Sr8Ev5Og@5.52:fOU1RGxh@6/Substance-Use-and-Abuse https://creativecommons.org/licenses/by/4.0/ https://commons.wikimedia.org/wiki/File:Mandelbrot_Islands_of_Consciousness https://creativecommons.org/licenses/by-sa/4.0/ https://creativecommons.org/licenses/by-sa/4.0/ https://creativecommons.org/about/pdm https://youtu.be/9PW1fwKjo-Y?list=PL8dPuuaLjXtOPRKzVLY0jJY-uHOH9KVU6 Figure 1. Popular portrayals of hypnosis have led to some widely-held misconceptions. TRY ITTRY IT hypnosis usually have clear memories of the hypnotic experience and are in control of their own behaviors. While hypnosis may be useful in enhancing memory or a skill, such enhancements are very modest in nature (Raz, 2011). How exactly does a hypnotist bring a participant to a state of hypnosis? While there are variations, there are four parts that appear consistent in bringing people into the state of suggestibility associated with hypnosis (National Research Council, 1994). These components include: The participant is guided to focus on one thing, such as the hypnotist’s words or a ticking watch. The participant is made comfortable and is directed to be relaxed and sleepy. The participant is told to be open to the process of hypnosis, trust the hypnotist and let go. The participant is encouraged to use his or her imagination. These steps are conducive to being open to the heightened suggestibility of hypnosis. People vary in terms of their ability to be hypnotized, but a review of available research suggests that most people are at least moderately hypnotizable (Kihlstrom, 2013). Hypnosis in conjunction with other techniques is used for a variety of therapeutic purposes and has shown to be at least somewhat effective for pain management, treatment of depression and anxiety, smoking cessation, and weight loss (Alladin, 2012; Elkins, Johnson, & Fisher, 2012; Golden, 2012; Montgomery, Schnur, & Kravits, 2012). Some scientists are working to determine whether the power of suggestion can affect cognitive processes such as learning, with a view to using hypnosis in educational settings (Wark, 2011). Furthermore, there is some evidence that hypnosis can alter processes that were once thought to be automatic and outside the purview of voluntary control, such as reading (Lifshitz, Aubert Bonn, Fischer, Kashem, & Raz, 2013; Raz, Shapiro, Fan, & Posner, 2002). However, it should be noted that others have suggested that the automaticity of these processes remains intact (Augustinova & Ferrand, 2012). How does hypnosis work? Two theories attempt to answer this question: One theory views hypnosis as dissociation and the other theory views it as the performance of a social role. According to the dissociation view, hypnosis is effectively a dissociated state of consciousness, much like our earlier example where you may drive to work, but you are only minimally aware of the process of driving because your attention is focused elsewhere. This theory is supported by Ernest Hilgard’s research into hypnosis and pain. In Hilgard’s experiments, he induced participants into a state of hypnosis, and placed their arms into ice water. Participants were told they would not feel pain, but they could press a button if they did; while they reported not feeling pain, they did, in fact, press the button, suggesting a dissociation of consciousness while in the hypnotic state (Hilgard & Hilgard, 1994). Taking a different approach to explain hypnosis, the social-cognitive theory of hypnosis sees people in hypnotic states as performing the social role of a hypnotized person. As you will learn when you study social roles, people’s behavior can be shaped by their expectations of how they should act in a given situation. Some view a hypnotized person’s behavior not as an altered or dissociated state of consciousness, but as their fulfillment of the social expectations for that role. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=137 Figure 2. (a) This is a statue of a meditating Buddha, representing one of the many religious traditions of which meditation plays a part. (b) People practicing meditation may experience an alternate state of consciousness. (credit a: modification of work by Jim Epler; credit b: modification of work by Caleb Roenigk) Meditation MeditationMeditation is the act of focusing on a single target (such as the breath or a repeated sound) to increase awareness of the moment. While hypnosis is generally achieved through the interaction of a therapist and the person being treated, an individual can perform meditation alone. Often, however, people wishing to learn to meditate receive some training in techniques to achieve a meditative state. A meditative state, as shown by EEG recordings of newly-practicing meditators, is not an altered state of consciousness per se; however, patterns of brain waves exhibited by expert meditators may represent a unique state of consciousness (Fell, Axmacher, & Haupt, 2010). Although there are a number of different techniques in use, the central feature of all meditation is clearing the mind in order to achieve a state of relaxed awareness and focus (Chen et al., 2013; Lang et al., 2012). Mindfulness meditation has recently become popular. In the variation of meditation, the meditator’s attention is focused on some internal process or an external object (Zeidan, Grant, Brown, McHaffie, & Coghill, 2012). Meditative techniques have their roots in religious practices (Figure 2), but their use has grown in popularity among practitioners of alternative medicine. Research indicates that meditation may help reduce blood pressure, and the American Heart Association suggests that meditation might be used in conjunction with more traditional treatments as a way to manage hypertension, although there is not sufficient data for a recommendation to be made (Brook et al., 2013). Like hypnosis, meditation also shows promise in stress management, sleep quality (Caldwell, Harrison, Adams, Quin, & Greeson, 2010), treatment of mood and anxiety disorders (Chen et al., 2013; Freeman et al., 2010; Vøllestad, Nielsen, & Nielsen, 2012), and pain management (Reiner, Tibi, & Lipsitz, 2013). LINK TO LEARNINGLINK TO LEARNING Watch this video describe the results of a brain imaging study in individuals who underwent specific mindfulness-meditative techniques. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=137 TRY ITTRY IT GLOSSARYGLOSSARY hypnosishypnosis: state of extreme self-focus and attention in which minimal attention is given to external stimuli meditationmeditation: clearing the mind in order to achieve a state of relaxed awareness and focus An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=137 THINK IT OVERTHINK IT OVER • Under what circumstances would you be willing to consider hypnosis and/or meditation as a treatment option? What kind of information would you need before you made a decision to use these techniques? Licensing & AttributionsLicensing & Attributions CC licensed content, Shared previouslyCC licensed content, Shared previously • Other States of Consciousness. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.49:-J7Q2uv1@6/Other-States-of-Consciousness. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/content/col11629/latest/. PUTTING IT TOGETHER: STATES OF CONSCIOUSNESS LEARNING OBJECTIVESLEARNING OBJECTIVES In this module, you learned to: https://www.bbc.com/news/health-16406814 http://cnx.org/contents/Sr8Ev5Og@5.49:-J7Q2uv1@6/Other-States-of-Consciousness https://creativecommons.org/licenses/by/4.0/ LINK TO LEARNINGLINK TO LEARNING Visit the NYTimes article, “You Draw It: Just How Bad Is the Drug Overdose Epidemic?” to take a look at current trends and the alarming amount of deaths caused by drug overdoses. A 2017 survey in Utah found that about 80 percent of heroin users started with prescription drugs. • describe consciousness and biological rhythms • describe what happens to the brain and body during sleep • explain how drugs affect consciousness Remember that psychology is the study of the mind and behavior. Consider how your behavior is affected by varying states of consciousness—what happens if you don’t get enough sleep? How does your concentration and mood change? What happens to your conscious awareness when you take strong medications or drugs? In this module, you learned that varying states of consciousness, whether it be tiredness from jet lag, deep sleep, daydreaming, alcohol or drug use, hypnosis, or meditation, can all change physiological components in the mind as well as behavior. While we have control over some of these altered states, like meditation, there are sometimes variables outside of our control that lead to things like sleep disorders. Drug use often begins as a personal choice or something prescribed by a doctor, but many drugs have addictive qualities that make them hard to put down. Substance abuse disorders can develop out of drug use, and those with drug addictions struggle with physical and psychological dependence on the drug. This is an especially important issue for us today because death by drug overdoses has been dramatically increasing over the past few years. Take a look at the interactive below to see the increasing prevalence of drug overdoses. As you read in the article above, in 2015 there were 52,000 American deaths from all drug overdoses. Two thirds of them, 33,000, were from opioids, compared to 16,000 in 2010 and 4,000 in 1999. Death from opioid drug overdoses were nearly equal to the number of deaths from car crashes, with deaths from heroin alone accounting for more deaths than from gun violence. In 2016, deaths from overdoses increased over the previous year by 26% in Connecticut, 35% in Delaware, 39% in Maine, and 62% in Maryland. Nearly half of all opioid overdose deaths involve a prescription opioid. The governor of Maryland declared a State of Emergency in March 2017 to combat the epidemic and CDC director Thomas Frieden has said that “America is awash in opioids; urgent action is critical.” With this sudden, extreme increase in drug overdoses, psychologists and psychiatrists will continue to play an important role in researching, educating, and preventing substance abuse disorders. You can read more about what researchers are doing at the Addiction Connection or even find some practical tips on ways to prevent a drug overdose in this article from Psychology Today. Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution CC licensed content, Shared previouslyCC licensed content, Shared previously • Opioid Epidemic. Provided byProvided by: Wikipedia. Located atLocated at: https://en.wikipedia.org/wiki/Opioid_epidemic. LicenseLicense: CC BY-SA: Attribution-ShareAlike • Generic temazepam 10 mg tablets. Provided byProvided by: Wikipedia. Located atLocated at: https://en.wikipedia.org/wiki/Temazepam#/media/File:Temazepam_10mg_tablets-1 . LicenseLicense: CC BY-SA: Attribution-ShareAlike https://youtu.be/3mufsteNrTI https://www.nytimes.com/interactive/2017/04/14/upshot/drug-overdose-epidemic-you-draw-it.html https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/11/26123017/1280px-Temazepam_10mg_tablets-1 https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2016/11/26123017/1280px-Temazepam_10mg_tablets-1 https://www.psychologytoday.com/blog/the-addiction-connection https://www.psychologytoday.com/blog/the-addiction-connection/201407/how-prevent-drug-overdose https://creativecommons.org/licenses/by/4.0/ https://en.wikipedia.org/wiki/Opioid_epidemic https://creativecommons.org/licenses/by-sa/4.0/ https://en.wikipedia.org/wiki/Temazepam#/media/File:Temazepam_10mg_tablets-1 https://creativecommons.org/licenses/by-sa/4.0/ DISCUSSION: STATES OF CONSCIOUSNESS Sleep Stages STEP 1STEP 1: Respond to the following in a primary post of at least 150-200 words: • What are the stages of sleep and what is the importance of sleep? • Most of us feel like we never get enough sleep. What can you do to improve your sleep and improve your consciousness during waking hours? STEP 2STEP 2: Thoughtfully respond to a minimum of 2 classmates with secondary posts of at least 75-100 words. Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Discussion: States of Consciousness. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution CC licensed content, Shared previouslyCC licensed content, Shared previously • Discussion ideas. Authored byAuthored by: Terry Davis . Provided byProvided by: Wiley College. LicenseLicense: CC BY: Attribution https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ MODULE 6: LEARNING WHY IT MATTERS: LEARNING Figure 1. Loggerhead sea turtle hatchlings are born knowing how to find the ocean and how to swim. Unlike the sea turtle, humans must learn how to swim (and surf). (credit “turtle”: modification of work by Becky Skiba, USFWS; credit “surfer”: modification of work by Mike Baird) The summer sun shines brightly on a deserted stretch of beach. Suddenly, a tiny grey head emerges from the sand, then another and another. Soon the beach is teeming with loggerhead sea turtle hatchlings (Figure 1). Although only minutes old, the hatchlings know exactly what to do. Their flippers are not very efficient for moving across the hot sand, yet they continue onward, instinctively. Some are quickly snapped up by gulls circling overhead and others become lunch for hungry ghost crabs that dart out of their holes. Despite these dangers, the hatchlings are driven to leave the safety of their nest and find the ocean. Not far down this same beach, Ben and his son, Julian, paddle out into the ocean on surfboards. A wave approaches. Julian crouches on his board, then jumps up and rides the wave for a few seconds before losing his balance. He emerges from the water in time to watch his father ride the face of the wave. Unlike baby sea turtles, which know how to find the ocean and swim with no help from their parents, we are not born knowing how to swim (or surf). Yet we humans pride ourselves on our ability to learn. In fact, over thousands of years and across cultures, we have created institutions devoted entirely to learning. But have you ever asked yourself how exactly it is that we learn? What processes are at work as we come to know what we know? This module focuses on the primary ways in which learning occurs. AnswerAnswer Anderson, C. A., & Gentile, D. A. (2008). Media violence, aggression, and public policy. In E. Borgida & S. Fiske (Eds.), Beyond common sense: Psychological science in the courtroom (p. 322). Malden, MA: Blackwell. Bandura, A., Ross, D., & Ross, S. A. (1961). Transmission of aggression through imitation of aggressive models. Journal of Abnormal and Social Psychology, 63, 575–582. Cangi, K., & Daly, M. (2013). The effects of token economies on the occurrence of appropriate and inappropriate behaviors by children with autism in a social skills setting. West Chester University: Journal of Undergraduate Research. Retrieved from http://www.wcupa.edu/UndergraduateResearch/journal/documents/cangi_S2012 Carlson, L., Holscher, C., Shipley, T., & Conroy Dalton, R. (2010). Getting lost in buildings. Current Directions in Psychological Science, 19(5), 284–289. Cialdini, R. B. (2008). Influence: Science and practice (5th ed.). Boston, MA: Pearson Education. Chance, P. (2009). Learning and behavior (6th ed.). Belmont, CA: Wadsworth, Cengage Learning. DeAngelis, T. (2010). ‘Little Albert’ regains his identity. Monitor on Psychology, 41(1), 10. Franzen, H. (2001, May 24). Gambling, like food and drugs, produces feelings of reward in the brain. Scientific American [online]. Retrieved from http://www.scientificamerican.com/article.cfm?id=gamblinglike-food-and-dru Fryer, R. G., Jr. (2010, April). Financial incentives and student achievement: Evidence from randomized trials. National Bureau of Economic Research [NBER] Working Paper, No. 15898. Retrieved from http://www.nber.org/ papers/w15898 Garcia, J., & Koelling, R. A. (1966). Relation of cue to consequence in avoidance learning. Psychonomic Science, 4, 123–124. Garcia, J., & Rusiniak, K. W. (1980). What the nose learns from the mouth. In D. Müller-Schwarze & R. M. Silverstein (Eds.), Chemical signals: Vertebrates and aquatic invertebrates (pp. 141–156). New York, NY: Plenum Press. Gershoff, E. T. (2002). Corporal punishment by parents and associated child behaviors and experiences: A meta- analytic and theoretical review. Psychological Bulletin, 128(4), 539–579. doi:10.1037//0033-2909.128.4.539 Gershoff, E.T., Grogan-Kaylor, A., Lansford, J. E., Chang, L., Zelli, A., Deater-Deckard, K., & Dodge, K. A. (2010). Parent discipline practices in an international sample: Associations with child behaviors and moderation by perceived normativeness. Child Development, 81(2), 487–502. Hickock, G. (2010). The role of mirror neurons in speech and language processing. Brain and Language, 112, 1–2. Holmes, S. (1993). Food avoidance in patients undergoing cancer chemotherapy. Support Care Cancer, 1(6), 326–330. Hunt, M. (2007). The story of psychology. New York, NY: Doubleday. Huston, A. C., Donnerstein, E., Fairchild, H., Feshbach, N. D., Katz, P. A., Murray, J. P., . . . Zuckerman, D. (1992). Big world, small screen: The role of television in American society. Lincoln, NE: University of Nebraska Press. Hutton, J. L., Baracos, V. E., & Wismer, W. V. (2007). Chemosensory dysfunction is a primary factor in the evolution of declining nutritional status and quality of life with patients with advanced cancer. Journal of Pain Symptom Management, 33(2), 156–165. Illinois Institute for Addiction Recovery. (n.d.). WTVP on gambling. Retrieved from http://www.addictionrecov.org/ InTheNews/Gambling/ Jacobsen, P. B., Bovbjerg, D. H., Schwartz, M. D., Andrykowski, M. A., Futterman, A. D., Gilewski, T., . . . Redd, W. H. (1993). Formation of food aversions in cancer patients receiving repeated infusions of chemotherapy. Behaviour Research and Therapy, 31(8), 739–748. Kirsch, SJ (2010). Media and youth: A developmental perspective. Malden MA: Wiley Blackwell. Lefrançois, G. R. (2012). Theories of human learning: What the professors said (6th ed.). Belmont, CA: Wadsworth, Cengage Learning. Miller, L. E., Grabell, A., Thomas, A., Bermann, E., & Graham-Bermann, S. A. (2012). The associations between community violence, television violence, intimate partner violence, parent-child aggression, and aggression in sibling relationships of a sample of preschoolers. Psychology of Violence, 2(2), 165–78. doi:10.1037/a0027254 Murrell, A., Christoff, K. & Henning, K. (2007) Characteristics of domestic violence offenders: associations with childhood exposure to violence. Journal of Family Violence, 22(7), 523-532. Pavlov, I. P. (1927). Conditioned reflexes: An investigation of the physiological activity of the cerebral cortex (G. V. Anrep, Ed. & Trans.). London, UK: Oxford University Press. Rizzolatti, G., Fadiga, L., Fogassi, L., & Gallese, V. (2002). From mirror neurons to imitation: Facts and speculations. In A. N. Meltzoff & W. Prinz (Eds.), The imitative mind: Development, evolution, and brain bases (pp. 247–66). Cambridge, United Kingdom: Cambridge University Press. Rizzolatti, G., Fogassi, L., & Gallese, V. (2006, November). Mirrors in the mind. Scientific American [online], pp. 54–61. Roy, A., Adinoff, B., Roehrich, L., Lamparski, D., Custer, R., Lorenz, V., . . . Linnoila, M. (1988). Pathological gambling: A psychobiological study. Archives of General Psychiatry, 45(4), 369–373. doi:10.1001/ archpsyc.1988.01800280085011 Skinner, B. F. (1938). The behavior of organisms: An experimental analysis. New York, NY: Appleton-Century- Crofts. Skinner, B. F. (1953). Science and human behavior. New York, NY: Macmillan. Skinner, B. F. (1961). Cumulative record: A selection of papers. New York, NY: Appleton-Century-Crofts. Skinner’s utopia: Panacea, or path to hell? (1971, September 20). Time [online]. Retrieved from http://www.wou.edu/~girodm/611/Skinner%27s_utopia Skolin, I., Wahlin, Y. B., Broman, D. A., Hursti, U-K. K., Larsson, M. V., & Hernell, O. (2006). Altered food intake and taste perception in children with cancer after start of chemotherapy: Perspectives of children, parents and nurses. Supportive Care in Cancer, 14, 369–78. Thorndike, E. L. (1911). Animal intelligence: An experimental study of the associative processes in animals. Psychological Monographs, 8. Tolman, E. C., & Honzik, C. H. (1930). Degrees of hunger, reward, and non-reward, and maze performance in rats. University of California Publications in Psychology, 4, 241–256. Tolman, E. C., Ritchie, B. F., & Kalish, D. (1946). Studies in spatial learning: II. Place learning versus response learning. Journal of Experimental Psychology, 36, 221–229. doi:10.1037/h0060262 Watson, J. B. & Rayner, R. (1920). Conditioned emotional reactions. Journal of Experimental Psychology, 3, 1–14. Watson, J. B. (1919). Psychology from the standpoint of a behaviorist. Philadelphia, PA: J. B. Lippincott. Yamamoto, S., Humle, T., & Tanaka, M. (2013). Basis for cumulative cultural evolution in chimpanzees: Social learning of a more efficient tool-use technique. PLoS ONE, 8(1): e55768. doi:10.1371/journal.pone.0055768 Licensing & AttributionsLicensing & Attributions CC licensed content, Shared previouslyCC licensed content, Shared previously • Introduction to Learning. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.52:Nc0-RFXN@4/Introduction. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/ content/col11629/latest/. http://cnx.org/contents/Sr8Ev5Og@5.52:Nc0-RFXN@4/Introduction https://creativecommons.org/licenses/by/4.0/ WHAT IS LEARNING? What you’ll learn to do: explain learning and the process of classical conditioning In this section, you’ll learn about learning. It might not be “learning” as you typically think of the word, because we’re not talking about going to school, or studying, or even effortfully trying to remember something. Instead, you’ll see that one of the main types of behavioral learning that we do is simply through an automatic process of association, known as classical conditioning. In classical conditioning, organisms learn to associate events that repeatedly happen together, and researchers study how a reflexive response to a stimulus can be mapped to a different stimulus—by training an association between the two stimuli. Ivan Pavlov’s experiments show how stimulus-response bonds are formed. Watson, the founder of behaviorism, was greatly influenced by Pavlov’s work. He tested humans by conditioning fear in an infant known as Little Albert. His findings suggest that classical conditioning can explain how some fears develop. LEARNING OBJECTIVESLEARNING OBJECTIVES • Recognize and define three basic forms of learning—classical conditioning, operant conditioning, and observational learning https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/855/2017/04/11014319/dog-580466_1920 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=176 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=176 TRY ITTRY IT Learning Birds build nests and migrate as winter approaches. Infants suckle at their mother’s breast. Dogs shake water off wet fur. Salmon swim upstream to spawn, and spiders spin intricate webs. What do these seemingly unrelated behaviors have in common? They all are unlearned behaviors. Both instincts and reflexes are innate behaviors that organisms are born with. ReflexesReflexes are a motor or neural reaction to a specific stimulus in the environment. They tend to be simpler than instincts, involve the activity of specific body parts and systems (e.g., the knee-jerk reflex and the contraction of the pupil in bright light), and involve more primitive centers of the central nervous system (e.g., the spinal cord and the medulla). In contrast, instinctsinstincts are innate behaviors that are triggered by a broader range of events, such as aging and the change of seasons. They are more complex patterns of behavior, involve movement of the organism as a whole (e.g., sexual activity and migration), and involve higher brain centers. Both reflexes and instincts help an organism adapt to its environment and do not have to be learned. For example, every healthy human baby has a sucking reflex, present at birth. Babies are born knowing how to suck on a nipple, whether artificial (from a bottle) or human. Nobody teaches the baby to suck, just as no one teaches a sea turtle hatchling to move toward the ocean. Learning, like reflexes and instincts, allows an organism to adapt to its environment. But unlike instincts and reflexes, learned behaviors involve change and experience: learning is a relatively permanent change in behavior or knowledge that results from experience. In contrast to the innate behaviors discussed above, learning involves acquiring knowledge and skills through experience. Looking back at our surfing scenario, Julian will have to spend much more time training with his surfboard before he learns how to ride the waves like his father. Learning to surf, as well as any complex learning process (e.g., learning about the discipline of psychology), involves a complex interaction of conscious and unconscious processes. Learning has traditionally been studied in terms of its simplest components—the associations our minds automatically make between events. Our minds have a natural tendency to connect events that occur closely together or in sequence. Associative learningAssociative learning occurs when an organism makes connections between stimuli or events that occur together in the environment. You will see that associative learning is central to all three basic learning processes discussed in this module; classical conditioning tends to involve unconscious processes, operant conditioning tends to involve conscious processes, and observational learning adds social and cognitive layers to all the basic associative processes, both conscious and unconscious. These learning processes will be discussed in detail later, but it is helpful to have a brief overview of each as you begin to explore how learning is understood from a psychological perspective. In classical conditioning, also known as Pavlovian conditioning, organisms learn to associate events—or stimuli—that repeatedly happen together. We experience this process throughout our daily lives. For example, you might see a flash of lightning in the sky during a storm and then hear a loud boom of thunder. The sound of the thunder naturally makes you jump (loud noises have that effect by reflex). Because lightning reliably predicts the impending boom of thunder, you may associate the two and jump when you see lightning. Psychological researchers study this associative process by focusing on what can be seen and measured—behaviors. Researchers ask if one stimulus triggers a reflex, can we train a different stimulus to trigger that same reflex? In operant conditioning, organisms learn, again, to associate events—a behavior and its consequence (reinforcement or punishment). A pleasant consequence encourages more of that behavior in the future, whereas a punishment deters the behavior. Imagine you are teaching your dog, Hodor, to sit. You tell Hodor to sit, and give Figure 1. In operant conditioning, a response is associated with a consequence. This dog has learned that certain behaviors result in receiving a treat. (credit: Crystal Rolfe) An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=176 LINK TO LEARNINGLINK TO LEARNING For a sneak peak and overview of the main different types of learning, watch the CrashCourse psychology below. We’ll learn about each of these topics in greater depth throughout this module. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=176 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=176 TRY ITTRY IT him a treat when he does. After repeated experiences, Hodor begins to associate the act of sitting with receiving a treat. He learns that the consequence of sitting is that he gets a doggie biscuit (Figure 1). Conversely, if the dog is punished when exhibiting a behavior, it becomes conditioned to avoid that behavior (e.g., receiving a small shock when crossing the boundary of an invisible electric fence). Observational learning extends the effective range of both classical and operant conditioning. In contrast to classical and operant conditioning, in which learning occurs only through direct experience, observational learning is the process of watching others and then imitating what they do. A lot of learning among humans and other animals comes from observational learning. To get an idea of the extra effective range that observational learning brings, consider Ben and his son Julian from the introduction. How might observation help Julian learn to surf, as opposed to learning by trial and error alone? By watching his father, he can imitate the moves that bring success and avoid the moves that lead to failure. Can you think of something you have learned how to do after watching someone else? All of the approaches covered in this module are part of a particular tradition in psychology, called behaviorism. However, these approaches you’ll be introduced to do not represent the entire study of learning. Separate traditions of learning have taken shape within different fields of psychology, such as memory and cognition, so you will find that other sections of this book will round out your understanding of the topic. Over time these traditions tend to converge. For example, in this module you will see how cognition has come to play a larger role in behaviorism, whose more extreme adherents once insisted that behaviors are triggered by the environment with no intervening thought. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=176 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=176 GLOSSARYGLOSSARY associative learning:associative learning: form of learning that involves connecting certain stimuli or events that occur together in the environment (classical and operant conditioning) instinct:instinct: unlearned knowledge, involving complex patterns of behavior; instincts are thought to be more prevalent in lower animals than in humans learning:learning: change in behavior or knowledge that is the result of experience reflex:reflex: unlearned, automatic response by an organism to a stimulus in the environment THINK IT OVERTHINK IT OVER • What is your personal definition of learning? How do your ideas about learning compare with the definition of learning presented in this text? • What kinds of things have you learned through the process of classical conditioning? Operant conditioning? Observational learning? How did you learn them? Licensing & AttributionsLicensing & Attributions CC licensed content, OriginalCC licensed content, Original • Modification, adaptation, and original content. Provided byProvided by: Lumen Learning. LicenseLicense: CC BY: Attribution CC licensed content, Shared previouslyCC licensed content, Shared previously • What is Learning?. Authored byAuthored by: OpenStax College. Located atLocated at: http://cnx.org/contents/Sr8Ev5Og@5.52:QNyXkiP7@5/What-Is-Learning. LicenseLicense: CC BY: Attribution. License TermsLicense Terms: Download for free at http://cnx.org/ content/col11629/latest/. • dog picture. Authored byAuthored by: skeeze. Located atLocated at: https://pixabay.com/en/dog-canine-labrador-retriever-580466/. LicenseLicense: CC0: No Rights Reserved All rights reserved contentAll rights reserved content • How to Train a Brain - Crash Course Psychology #11. Provided byProvided by: CrashCourse. Located atLocated at: https://youtu.be/qG2SwE_6uVM?list=PL8dPuuaLjXtOPRKzVLY0jJY-uHOH9KVU6. LicenseLicense: Other. License TermsLicense Terms: Standard YouTube License CLASSICAL CONDITIONING LEARNING OBJECTIVESLEARNING OBJECTIVES • Explain how classical conditioning occurs • Identify the NS, UCS, UCR, CS, and CR in classical conditioning situations • Describe the processes of acquisition, extinction, spontaneous recovery, generalization, and discrimination https://creativecommons.org/licenses/by/4.0/ http://cnx.org/contents/Sr8Ev5Og@5.52:QNyXkiP7@5/What-Is-Learning https://creativecommons.org/licenses/by/4.0/ https://pixabay.com/en/dog-canine-labrador-retriever-580466/ https://creativecommons.org/about/cc0 https://youtu.be/qG2SwE_6uVM?list=PL8dPuuaLjXtOPRKzVLY0jJY-uHOH9KVU6 Figure 1. Ivan Pavlov’s research on the digestive system of dogs unexpectedly led to his discovery of the learning process now known as classical conditioning. Does the name Ivan Pavlov ring a bell? Even if you are new to the study of psychology, chances are that you have heard of Pavlov and his famous dogs. Pavlov (1849–1936), a Russian scientist, performed extensive research on dogs and is best known for his experiments in classical conditioning (Figure 1). As we discussed briefly in the previous section, classicalclassical conditioningconditioning is a process by which we learn to associate stimuli and, consequently, to anticipate events. Pavlov came to his conclusions about how learning occurs completely by accident. Pavlov was a physiologist, not a psychologist. Physiologists study the life processes of organisms, from the molecular level to the level of cells, organ systems, and entire organisms. Pavlov’s area of interest was the digestive system (Hunt, 2007). In his studies with dogs, Pavlov surgically implanted tubes inside dogs’ cheeks to collect saliva. He then measured the amount of saliva produced in response to various foods. Over time, Pavlov (1927) observed that the dogs began to salivate not only at the taste of food, but also at the sight of food, at the sight of an empty food bowl, and even at the sound of the laboratory assistants’ footsteps. Salivating to food in the mouth is reflexive, so no learning is involved. However, dogs don’t naturally salivate at the sight of an empty bowl or the sound of footsteps. These unusual responses intrigued Pavlov, and he wondered what accounted for what he called the dogs’ “psychic secretions” (Pavlov, 1927). To explore this phenomenon in an objective manner, Pavlov designed a series of carefully controlled experiments to see which stimuli would cause the dogs to salivate. He was able to train the dogs to salivate in response to stimuli that clearly had nothing to do with food, such as the sound of a bell, a light, and a touch on the leg. Through his experiments, Pavlov realized that an organism has two types of responses to its environment: (1) unconditioned (unlearned) responses, or reflexes, and (2) conditioned (learned) responses. In Pavlov’s experiments, the dogs salivated each time meat powder was presented to them. The meat powder in this situation was an unconditioned stimulus (UCS)unconditioned stimulus (UCS): a stimulus that elicits a reflexive response in an organism. The dogs’ salivation was an unconditioned response (UCR)unconditioned response (UCR): a natural (unlearned) reaction to a given stimulus. Before conditioning, think of the dogs’ stimulus and response like this: Meat powder (UCS) → Salivation (UCR)Meat powder (UCS) → Salivation (UCR) In classical conditioning, a neutral stimulusneutral stimulus is presented immediately before an unconditioned stimulus. Pavlov would sound a tone (like ringing a bell) and then give the dogs the meat powder (Figure 2). The tone was the neutral stimulus (NS), which is a stimulus that does not naturally elicit a response. Prior to conditioning, the dogs did not salivate when they just heard the tone because the tone had no association for the dogs. Quite simply this pairing means: Tone (NS) + Meat Powder (UCS) → Salivation (UCR)Tone (NS) + Meat Powder (UCS) → Salivation (UCR) When Pavlov paired the tone with the meat powder over and over again, the previously neutral stimulus (the tone) also began to elicit salivation from the dogs. Thus, the neutral stimulus became the conditioned stimulus (CS)conditioned stimulus (CS), which is a stimulus that elicits a response after repeatedly being paired with an unconditioned stimulus. Eventually, the dogs began to salivate to the tone alone, just as they previously had salivated at the sound of the assistants’ footsteps. The behavior caused by the conditioned stimulus is called the conditioned response (CR)conditioned response (CR). In the case of Pavlov’s dogs, they had learned to associate the tone (CS) with being fed, and they began to salivate (CR) in anticipation of food. Tone (CS) → Salivation (CR)Tone (CS) → Salivation (CR) Figure 2. Before conditioning, an unconditioned stimulus (food) produces an unconditioned response (salivation), and a neutral stimulus (bell) does not produce a response. During conditioning, the unconditioned stimulus (food) is presented repeatedly just after the presentation of the neutral stimulus (bell). After conditioning, the neutral stimulus alone produces a conditioned response (salivation), thus becoming a conditioned stimulus. LINK TO LEARNINGLINK TO LEARNING Now that you have learned about the process of classical conditioning, do you think you can condition Pavlov’s dog? Visit this website to play the game. Next, view the following video to learn more about Pavlov and his dogs: An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2297 TRY ITTRY IT https://www.nobelprize.org/educational/medicine/pavlov/pavlov.html A YouTube element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2297 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2297 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2297 Real World Application of Classical Conditioning How does classical conditioning work in the real world? Let’s say you have a cat named Tiger, who is quite spoiled. You keep her food in a separate cabinet, and you also have a special electric can opener that you use only to open cans of cat food. For every meal, Tiger hears the distinctive sound of the electric can opener (“zzhzhz”) and then gets her food. Tiger quickly learns that when she hears “zzhzhz” she is about to get fed. What do you think Tiger does when she hears the electric can opener? She will likely get excited and run to where you are preparing her food. This is an example of classical conditioning. In this case, what are the UCS, CS, UCR, and CR?What if the cabinet holding Tiger’s food becomes squeaky? In that case, Tiger hears “squeak” (the cabinet), “zzhzhz” (the electric can opener), and then she gets her food. Tiger will learn to get excited when she hears the “squeak” of the cabinet. Pairing a new neutral stimulus (“squeak”) with the conditioned stimulus (“zzhzhz”) is called higher-order conditioning, or second-order conditioning. This means you are using the conditioned stimulus of the can opener to condition another stimulus: the squeaky cabinet (Figure 3). It is hard to achieve anything above second-order conditioning. For example, if you ring a bell, open the cabinet (“squeak”), use the can opener (“zzhzhz”), and then feed Tiger, Tiger will likely never get excited when hearing the bell alone. Figure 3. In higher-order conditioning, an established conditioned stimulus is paired with a new neutral stimulus (the second-order stimulus), so that eventually the new stimulus also elicits the conditioned response, without the initial conditioned stimulus being presented. LINK TO LEARNINGLINK TO LEARNING Get some more practice with classical conditioning through the following PsychSim Tutorial. The tutorial is only intended for practice. Please disregard the final screen that requests you submit answers to your instructor. • Classical Conditioning Figure 4. Kate holds a southern stingray at Stingray City in the Cayman Islands. These stingrays have been classically conditioned to associate the sound of a boat motor with food provided by tourists. (credit: Kathryn Dumper) EVERYDAY CONNECTION: CLASSICAL CONDITIONING AT STINGRAY CITYEVERYDAY CONNECTION: CLASSICAL CONDITIONING AT STINGRAY CITY Kate and her husband Scott recently vacationed in the Cayman Islands, and booked a boat tour to Stingray City, where they could feed and swim with the southern stingrays. The boat captain explained how the normally solitary stingrays have become accustomed to interacting with humans. About 40 years ago, fishermen began to clean fish and conch (unconditioned stimulus) at a particular sandbar near a barrier reef, and large numbers of stingrays would swim in to eat (unconditioned response) what the fishermen threw into the water; this continued for years. By the late 1980s, word of the large group of stingrays spread among scuba divers, who then started feeding them by hand. Over time, the southern stingrays in the area were classically conditioned much like Pavlov’s dogs. When they hear the sound of a boat engine (neutral stimulus that becomes a conditioned stimulus), they know that they will get to eat (conditioned response). As soon as Kate and Scott reached Stingray City, over two dozen stingrays surrounded their tour boat. The couple slipped into the water with bags of squid, the stingrays’ favorite treat. The swarm of stingrays bumped and rubbed up against their legs like hungry cats (Figure 4). Kate and Scott were able to feed, pet, and even kiss (for luck) these amazing creatures. Then all the squid was gone, and so were the stingrays. LINK TO LEARNINGLINK TO LEARNING For a humorous look at conditioning, watch the following from the television show The Office, where Jim conditions Dwight to expect a breath mint every time Jim’s computer makes a specific sound. See if you can identify the NS, UCS, UCR, CS, and CR. Classical conditioning also applies to humans, even babies. For example, Sara buys formula in blue canisters for her six-month-old daughter, Angelina. Whenever Sara takes out a formula container, Angelina gets excited, tries to reach toward the food, and most likely salivates. Why does Angelina get excited when she sees the formula canister? What are the UCS, CS, UCR, and CR here? So far, all of the examples have involved food, but classical conditioning extends beyond the basic need to be fed. Consider our earlier example of a dog whose owners install an invisible electric dog fence. A small electrical shock (unconditioned stimulus) elicits discomfort (unconditioned response). When the unconditioned stimulus (shock) is paired with a neutral stimulus (the edge of a yard), the dog associates the discomfort (unconditioned response) with the edge of the yard (conditioned stimulus) and stays within the set boundaries. http://bcs.worthpublishers.com/webpub/Ektron/Myers_Psychology%2010e/PsychSim5_Tutorials/ClassicalConditioning/ClassicalConditioning.htm An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2297 The Office Classical Conditioning from Susann Stanley on Vimeo. An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2297 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2297 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2297 TRY ITTRY IT THINK IT OVERTHINK IT OVER Can you think of an example in your life of how classical conditioning has produced a positive emotional response, such as happiness or excitement? How about a negative emotional response, such as fear, anxiety, or anger? Processes in Classical Conditioning Now that you know how classical conditioning works and have seen several examples, let’s take a look at some of the general processes involved. In classical conditioning, the initial period of learning is known as acquisition, when an organism learns to connect a neutral stimulus and an unconditioned stimulus. During acquisitionacquisition, the neutral stimulus begins to elicit the conditioned response, and eventually the neutral stimulus becomes a conditioned stimulus capable of eliciting the conditioned response by itself. Timing is important for conditioning to occur. Typically, there should only be a brief interval between presentation of the conditioned stimulus and the unconditioned stimulus. Depending on what is being conditioned, sometimes this interval is as little as five seconds (Chance, 2009). However, with other types of conditioning, the interval can be up to several hours. Taste aversionTaste aversion is a type of conditioning in which an interval of several hours may pass between the conditioned stimulus (something ingested) and the unconditioned stimulus (nausea or illness). Here’s how it works. Between classes, you and a friend grab a quick lunch from a food cart on campus. You share a dish of chicken curry and head off to your next class. A few hours later, you feel nauseous and become ill. Although your friend is fine and you determine that you have intestinal flu (the food is not the culprit), you’ve developed a taste aversion; the next time you are at a restaurant and someone orders curry, you immediately feel ill. While the chicken dish is not what made you sick, you are experiencing taste aversion: you’ve been conditioned to be averse to a food after a single, unpleasant experience. https://vimeo.com/35754924 https://vimeo.com/user10186722 https://vimeo.com How does this occur—conditioning based on a single instance and involving an extended time lapse between the event and the unpleasant stimulus? Research into taste aversion suggests that this response may be an evolutionary adaptation designed to help organisms quickly learn to avoid harmful foods (Garcia & Rusiniak, 1980; Garcia & Koelling, 1966). Not only may this contribute to species survival via natural selection, but it may also help us develop strategies for challenges such as helping cancer patients through the nausea induced by certain treatments (Holmes, 1993; Jacobsen et al., 1993; Hutton, Baracos, & Wismer, 2007; Skolin et al., 2006). Once we have established the connection between the unconditioned stimulus and the conditioned stimulus, how do we break that connection and get the dog, cat, or child to stop responding? In Tiger’s case, imagine what would happen if you stopped using the electric can opener for her food and began to use it only for human food. Now, Tiger would hear the can opener, but she would not get food. In classical conditioning terms, you would be giving the conditioned stimulus, but not the unconditioned stimulus. Pavlov explored this scenario in his experiments with dogs: sounding the tone without giving the dogs the meat powder. Soon the dogs stopped responding to the tone. ExtinctionExtinction is the decrease in the conditioned response when the unconditioned stimulus is no longer presented with the conditioned stimulus. When presented with the conditioned stimulus alone, the dog, cat, or other organism would show a weaker and weaker response, and finally no response. In classical conditioning terms, there is a gradual weakening and disappearance of the conditioned response. What happens when learning is not used for a while—when what was learned lies dormant? As we just discussed, Pavlov found that when he repeatedly presented the bell (conditioned stimulus) without the meat powder (unconditioned stimulus), extinction occurred; the dogs stopped salivating to the bell. However, after a couple of hours of resting from this extinction training, the dogs again began to salivate when Pavlov rang the bell. What do you think would happen with Tiger’s behavior if your electric can opener broke, and you did not use it for several months? When you finally got it fixed and started using it to open Tiger’s food again, Tiger would remember the association between the can opener and her food—she would get excited and run to the kitchen when she heard the sound. The behavior of Pavlov’s dogs and Tiger illustrates a concept Pavlov called spontaneous recovery: the return of a previously extinguished conditioned response following a rest period (Figure 5). Figure 5. This is the curve of acquisition, extinction, and spontaneous recovery. The rising curve shows the conditioned response quickly getting stronger through the repeated pairing of the conditioned stimulus and the unconditioned stimulus (acquisition). Then the curve decreases, which shows how the conditioned response weakens when only the conditioned stimulus is presented (extinction). After a break or pause from conditioning, the conditioned response reappears (spontaneous recovery). Of course, these processes also apply in humans. For example, let’s say that every day when you walk to campus, an ice cream truck passes your route. Day after day, you hear the truck’s music (neutral stimulus), so you finally stop and purchase a chocolate ice cream bar. You take a bite (unconditioned stimulus) and then your mouth waters (unconditioned response). This initial period of learning is known as acquisition, when you begin to connect the neutral stimulus (the sound of the truck) and the unconditioned stimulus (the taste of the chocolate ice cream in your mouth). During acquisition, the conditioned response gets stronger and stronger through repeated pairings of the conditioned stimulus and unconditioned stimulus. Several days (and ice cream bars) later, you notice that your mouth begins to water (conditioned response) as soon as you hear the truck’s musical jingle—even before you bite into the ice cream bar. Then one day you head down the street. You hear the truck’s music (conditioned stimulus), and your mouth waters (conditioned response). However, when you get to the truck, you discover that they are all out of ice cream. You leave disappointed. The next few days you pass by the truck and hear the music, but don’t stop to get an ice cream bar because you’re running late for class. You begin to salivate less and less when you hear the music, until by the end of the week, your mouth no longer waters when you hear the tune. This illustrates extinction. The conditioned response weakens when only the conditioned stimulus (the sound of the truck) is presented, without being followed by the unconditioned stimulus (chocolate ice cream in the mouth). Then the weekend comes. You don’t have to go to class, so you don’t pass the truck. Monday morning arrives and you take your usual route to campus. You round the corner and hear the truck again. What do you think happens? Your mouth begins to water again. Why? After a break from conditioning, the conditioned response reappears, which indicates spontaneous recovery. Acquisition and extinction involve the strengthening and weakening, respectively, of a learned association. Two other learning processes—stimulus discrimination and stimulus generalization—are involved in distinguishing which stimuli will trigger the learned association. Animals (including humans) need to distinguish between An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2297 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2297 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2297 An interactive or media element has been excluded from this version of the text. You can view it online here: https://courses.lumenlearning.com/cochise-psychology/?p=2297 TRY ITTRY IT stimuli—for example, between sounds that predict a threatening event and sounds that do not—so that they can respond appropriately (such as running away if the sound is threatening). When an organism learns to respond differently to various stimuli that are similar, it is called stimulus discriminationstimulus discrimination. In classical conditioning terms, the organism demonstrates the conditioned response only to the conditioned stimulus. Pavlov’s dogs discriminated between the basic tone that sounded before they were fed and other tones (e.g., the doorbell), because the other sounds did not predict the arrival of food. Similarly, Tiger, the cat, discriminated between the sound of the can opener and the sound of the electric mixer. When the electric mixer is going, Tiger is not about to be fed, so she does not come running to the kitchen looking for food. On the other hand, when an organism demonstrates the conditioned response to stimuli that are similar to the condition stimulus, it is called stimulus generalizationstimulus generalization, the opposite of stimulus discrimination. The more similar a stimulus is to the condition stimulus, the more likely the organism is to give the conditioned response. For instance, if the electric mixer sounds very similar to the electric can opener, Tiger may come running after hearing its sound. But if you do not feed her following the electric mixer sound, and you continue to feed her consistently after the electric can opener sound, she will quickly learn to discriminate between the two sounds (provided they are sufficiently dissimilar that she can tell them apart). Sometimes, classical conditioning can lead to habituation. HabituationHabituation occurs when we learn not to respond to a stimulus that is presented repeatedly without change. As the stimulus occurs over and over, we learn not to focus our attention on it. For example, imagine that your neighbor or roommate constantly has the television blaring. This background noise is distracting and makes it difficult for you to focus when you’re studying. However, over time, you become accustomed to the stimulus of the television noise, and eventually you hardly notice it any longer. Classical Conditioning and Behaviorism John B. Watson, shown in Figure 6, is considered the founder of behaviorism. Behaviorism is a school of thought that arose during the first part of the 20th century, which incorporates elements of Pavlov’s classical conditioning (Hunt, 2007). In stark contrast with Freud, who considered the reasons for behavior to be hidden in the unconscious, Watson championed the idea that all behavior can be studied as a simple stimulus-response reaction, without regard for internal processes. Watson argued that in order for psychology to become a legitimate science, it must shift its concern away from internal mental processes because mental processes cannot be seen or measured. Instead, he asserted that psychology must focus on outward observable behavior that can be measured. Figure 6. John B. Watson used the principles of classical conditioning in the study of human emotion. Watson’s ideas were influenced by Pavlov’s work. According to Watson, human behavior, just like animal behavior, is primarily the result of conditioned responses. Whereas Pavlov’s work with dogs involved the conditioning of reflexes, Watson believed the same principles could be extended to the conditioning of human emotions (Watson, 1919). Thus began Watson’s work with his graduate student Rosalie Rayner and a baby called Little Albert. Through their experiments with Little Albert, Watson and Rayner (1920) demonstrated how fears can be conditioned. In 1920, Watson was the chair of the psychology department at Johns Hopkins University. Through his position at the university he came to meet Little Albert’s mother, Arvilla Merritte, who worked at a campus hospital (DeAngelis, 2010). Watson offered her a dollar to allow her son to be the subject of his experiments in classical conditioning. Through these experiments, Little Albert was exposed to and conditioned to fear certain things. Initially he was presented with various neutral stimuli, including a rabbit, a dog, a monkey, masks, cotton wool, and a white rat. He was not afraid of any of these things. Then Watson, with the help of Rayner, conditioned Little Albert to associate these stimuli with an emotion—fear. For example, Watson handed Little Albert the white rat, and Little Albert enjoyed playing with it. Then Watson made a loud sound, by striking a hammer against a metal bar hanging behind Little Albert’s head, each time Little Albert touched the rat. Little Albert was frightened by the sound—demonstrating a reflexive fear of sudden loud noises—and began to cry. Watson repeatedly paired the loud sound with the white rat. Soon Little Albert became frightened by the white ra

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