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BIOPSYCHOLOGY 8eJohn P.J. Pinel

Copyright © Pearson Education 2011

17.1 Biopsychology of Emotion: Introduction

17.2 Fear, Defense, and Aggression

17.3 Neural Mechanisms of Fear Conditioning

17.4 Stress and Health

17.5 Brain Mechanisms of Human Emotion

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Biopsychology of Emotion: Introduction

• Phineus Gage• Why would a tamping iron

through the skull lead to dramatic changes in personality?

• Damage to the medical prefrontal lobes• Site of planning and emotion


Darwin’s Theory of the Evolution of Emotional Expression

• Expressions of emotion evolve from behaviors that indicate what an animal is likely to do next

• If emotional signals are beneficial, they will evolve to more effectively communicate and may lose their original meaning

• Opposite messages are often signaled by opposite movements – “principle of antithesis”

• Threat displays, for example, are beneficial – intimidate victims without the costs and risks for fighting


James-Lange• Stimulus triggers autonomic/skeletal

response which triggers emotion• Autonomic/skeletal response

necessary for emotionCannon-Bard

• Stimulus triggers autonomic/skeletal response and emotion

• Autonomic/skeletal response independent of emotion

Theories of Emotion

BOTH ARE WRONG

BOTH ARE WRONG


FIGURE 17.3:Four ways of thinking about the relations among the perception of emotion-inducing stimuli, the autonomic and somatic responses to the stimuli, and the emotional experience.

Theories of Emotion


Sham RageSham Rage

• Decorticated cats exhibit extreme and unfocused aggressive responses

• Hypothalamus must be intact • Perhaps hypothalamus is

needed for expression of aggression and cortex serves to inhibit and direct responses

• Decorticated cats exhibit extreme and unfocused aggressive responses

• Hypothalamus must be intact • Perhaps hypothalamus is

needed for expression of aggression and cortex serves to inhibit and direct responses


Limbic System and Emotion

Papez proposed an emotional circuit (limbic system) that includes the hypothalamus

Papez proposed an emotional circuit (limbic system) that includes the hypothalamus


Kluver-Bucy Syndrome

•Rare cerebral neurological disorder•Major symptoms – urge to put objects into mouth, memory loss, extreme sexual behavior, placidity, visual distractibility

•Results from bilateral damage to anterior temporal lobes

•First seen in monkeys, then other species (including humans)


• Two important questions• Which patterns of ANS

activity are associated with specific emotions?

• Are ANS measures effective on polygraph (“lie detector”)?

• There is not a separate ANS profile for each emotion

motion and the Automatic Nervous System (ANS)

motion and the Automatic Nervous System (ANS)


Polygraphy

• Lie detection is really emotion detection• Control-question technique

• Physiological response to a target question compared with response to control question

• Success rate in studies is about 80%• Guilty knowledge technique

• Merely ask a question that only the culprit would know the answer to

• Success rate in distinguishing guilty vs. innocent is 88% in one study

• Lie detection is really emotion detection• Control-question technique

• Physiological response to a target question compared with response to control question

• Success rate in studies is about 80%• Guilty knowledge technique

• Merely ask a question that only the culprit would know the answer to

• Success rate in distinguishing guilty vs. innocent is 88% in one study


Emotions and Facial Expressions

• The meanings of facial expressions appear to be universal

• Six primary emotions

– Naturally occurring expressions are usually variations or combinations of the basic ones

• Facial feedback hypothesis – smiling makes you happier; facial muscles influence emotional experience

• Microexpressions – brief facial expressions reveal true feelings; may break through false ones

• Different muscles involved in fake and real smiles


Fear, Defense, and Aggression

• Fear – emotional reaction to threat• Aggressive behaviors – designed to

threaten or harm• Defensive behaviors – designed to

protect from threat or harm (motivated by fear)

• Social aggression – unprovoked attacks on members of one’s own species to establish dominance

• Defensive attack – aggressive behavior, as when cornered


Colony-intruder model of aggression and defense in rats• Study interaction between alpha

male of an established colony with a small male intruder

Observation of cats and mice• Cat “play” with prey is actually a

combination of attack and defense behaviors

Target-site concept – aggressive behaviors designed to attack specific sites on body, defensive to protect specific sites

Types of Aggressive and Defensive Behaviors


Aggression and Testosterone (T)

• Nonprimates – T release around birth of male rats prepares them for T-activated social aggression at maturity

• T increases or has no effect on social aggression, depending on species; castration decreases or has no effect on social aggression in same species

• In humans, social aggression does not increase along with higher T levels at puberty


Neural Mechanisms of Fear Conditioning

Fear conditioning• Pair a neutral stimulus (e.g., a tone) with

an aversive stimulus (e.g., a shock)• Present the tone later and the animal will

show a conditioned fear response– Usually a defensive behavior


Amygdala and Fear Conditioning

• Lesions of the amygdala block fear conditioning

• The amygdala receives input from all sensory systems

–Appears to be responsible for adding emotional significance to another stimulus

–Amygdala projects to brainstem regions that control emotional behavior output


Contextual Fear Conditioning and the Hippocampus

Pair an aversive stimulus with the context instead of with a discrete stimulus

• Hippocampus is linked to spatial memory

• Effect of bilateral hippocampal lesions on contextual fear conditioning

•Before training – prevents conditioning•Shortly after training – blocks retention of conditioning

Pair an aversive stimulus with the context instead of with a discrete stimulus

• Hippocampus is linked to spatial memory

• Effect of bilateral hippocampal lesions on contextual fear conditioning

•Before training – prevents conditioning•Shortly after training – blocks retention of conditioning


Amygdala Complex and Fear Conditioning

In addition, conditioned fear is suppressed by the prefrontal cortex inhibiting the lateral amygdala

The hippocampus mediates conditioned fear learning byinforming the lateral amyg-

dala about the context of the fear-related event

Current synthesis of findings indicates that the lateral

amygdala is most critical in conditioned

fear


• Stress – reaction to harm or threat• Stressors – stimuli that cause stress• Chronic psychological stress – most clearly

linked to ill health• In the short-term, stress is adaptive; in the

long-term, it is maladaptive

Stress and Health


The Stress Response

• Stress triggers stress hormone: anterior-pituitary adrenal-cortex system (glucocorticoids, epinephrine, and norepinephrine) and cytokines (causing inflammation and fever)

• Selye neglected sympathetic nervous system

• Individual differences, such as attitude, affect the magnitude of the stress response

–Example: women awaiting surgery who were “certain” they did not have breast cancer had milder stress than others


Animal Models of Stress

• Some early models used levels of stress that might not have a human equivalent

• Some more recent models use social stresses

• For example, subordination stress

• Some early models used levels of stress that might not have a human equivalent

• Some more recent models use social stresses

• For example, subordination stress


Psychosomatic Disorders: The Case of Gastric Ulcers

•Gastric ulcers – lesions of stomach lining and duodenum

•More common in those who are stressed; readily created in the animal lab

•Ulcers are caused by a bacteria – stress appears to make the body vulnerable to this bacteria

•75% of healthy subjects have the bacteria


Psychoneuroimmunology

The study of the interaction of psychological factors, the nervous system, and the immune system

Psychoneuroimmunology

The study of the interaction of psychological factors, the nervous system, and the immune system


Immune System

Divisions of the mammalian immune system

Innate immune system

• First line of defense

• Attacks generic classes of pathogens

Adaptive immune system

• Targets specific pathogens identified by their antigens

• Has memory (the basis of effectiveness of vaccination)

• Cytokines activate lymphocytes (white blood cells)

Innate immune system

• First line of defense

• Attacks generic classes of pathogens

Adaptive immune system

• Targets specific pathogens identified by their antigens

• Has memory (the basis of effectiveness of vaccination)

• Cytokines activate lymphocytes (white blood cells)


Two Adaptive Barriers to Infection


How Does Stress Influence Immune Function?

• Effects of stress on immune function depends on the kind of stress

–Acute stressors improve immune function

–Chronic stressors impair immune function

• Many ways that stress can impact immune function

–Effects of stress can be good (adaptive and healthful), bad, or mixed


Early Experience of Stress

• Stress of mistreatment early in life may cause brain and endocrine abnormalities later in life

• Rat pups handled by researchers had more adaptive stress response in adulthood (less circulating glucocorticoids following stress), probably due to less negative feedback from hippocampal glucocorticoid receptors

• A good example of epigenetic (“not of the genes”) transmission: fearful, poor-grooming mothers raise daughters who become fearful, poor-grooming mothers

• Stress of mistreatment early in life may cause brain and endocrine abnormalities later in life

• Rat pups handled by researchers had more adaptive stress response in adulthood (less circulating glucocorticoids following stress), probably due to less negative feedback from hippocampal glucocorticoid receptors

• A good example of epigenetic (“not of the genes”) transmission: fearful, poor-grooming mothers raise daughters who become fearful, poor-grooming mothers


Stress and the Hippocampus

• Hippocampus has many glucocorticoid receptors

• Following stress:– Dendrites of pyramidal cells are

shorter and less branched– Adult neurogenesis of granule

cells reduced• Effects blocked with

adrenalectomy; produced with corticosteroids


Brain Mechanisms of Human Emotion: Cognitive Neuroscience

Three main points have advanced the understanding of brain mechanisms of emotion:

• Brain activity associated with each human emotion is diffuse

• There is usually motor and sensory regional activity along with an emotional response

• Brain activity for experienced, imagined, or observed emotion is similar


• Early theories of emotion were general theories (e.g., limbic system theory – limbic system plays a role in all emotions)

• Recent discoveries: • From brain imaging, amygdala

activity is correlated with fear (especially social fear) and certain other negative emotions

• Urbach-Wiethe disease (calcification of amygdala) causes loss of facial expression and loss of recognition of fear

Amygdala in Human Emotion


Medial Prefrontal Lobes and Human Emotion

• Includes medial portions of the orbitofrontal cortex and cingulate cortex

• Site of emotion-cognitive interaction, especially cognitive suppression of emotional reactions

• Possible roles in comparison of outcome and expectancy, guiding behavior based on recent experience, response to social rejection


• Two theories:

• Right-hemisphere model – the right hemisphere is dominant for all aspects of emotion

• Valence model – the right hemisphere specializes in negative emotions

• Both theories are probably too general• Strong evidence for lateralization for

particular structures and emotions• Males may be more lateralized than

females

Lateralization of Emotion


Individual Differences in the Neural Mechanisms of Emotion

• Most (but not all) of nine patients with bilateral amygdalar lesions had difficulty recognizing fear in facial expressions (Adolphs and colleagues, 2003)

• Personality differences: both high extraversion and high neuroticism healthy subjects showed higher amygdalar activity while viewing fearful faces; only extraverts showed higher amygdalar activity while viewing happy faces (Canli and colleagues, 2002)


Watch: Gender Differences in StressVulnerability

Watch: Can Yoga or Meditation Help You Relax?

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Acknowledgments

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4 Man's head ©istockphoto.com/Nicolas Hansen

5, 33 left profile talking ©istockphoto.com/Digital Savant LLC

5, 33 right profile talking ©istockphoto.com/See Hear Media, Inc.

6 Figure 17.3 Pinel 8e, p. 445

7, 18, 29 brain ©istockphoto.com/Stephen Kirklys


9, 16 neuron ©istockphoto.com/ktsimage

10 person holding up baby ©istockphoto.com/Barbara Sauder

11 head - woman ©istockphoto.com/Angel Herrero de Frutos

12, 34 variety of facial expressions ©istockphoto.com/ZoneCreative

13 barking dog ©iStockphoto.com/Yuriy Zelenenkyy

14 silhouettes - hate fighting TrapdoorMedia

15 punch through wall ©istockphoto.com/Sami Suni


20 person reading books ©iStockphoto.com/Francesco Ridolfi


22 white rat ©iStockphoto.com/Elena Butinova


Acknowledgments

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27 college age person coughing ©istockphoto.com/Sharon Barnes Photography

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