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BIOPSYCHOLOGY 8e
John P.J. Pinel
Copyright © Pearson Education 2011
Topics
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
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
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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
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Theories of Emotion
James-Lange
• Stimulus triggers autonomic/skeletal
response which triggers emotion
• Autonomic/skeletal response
necessary for emotion
Cannon-Bard
• Stimulus triggers autonomic/skeletal
response and emotion
• Autonomic/skeletal response
independent of emotion
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Theories of Emotion
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.
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Sham 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
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Limbic System and Emotion
Papez proposed an
emotional circuit
(limbic system) that
includes the
hypothalamus
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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)
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motion and the Automatic
Nervous System (ANS)
• 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
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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
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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
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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
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Types of Aggressive and Defensive Behaviors
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
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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
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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
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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
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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
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Amygdala Complex and Fear Conditioning
Current synthesis of findings
indicates that the lateral
amygdala is most critical in
conditioned
fear
The hippocampus mediates
conditioned fear learning by
informing the lateral amygdala about the context of the
fear-related event
In addition, conditioned fear
is suppressed by the
prefrontal cortex inhibiting
the lateral amygdala
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Stress and Health
• 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
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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
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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
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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
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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)
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Two Adaptive Barriers to Infection
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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
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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, poorgrooming mothers raise daughters who
become fearful, poor-grooming mothers
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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
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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
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Amygdala in Human Emotion
• 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
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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
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Lateralization of Emotion
• 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
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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)
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Watch: Gender Differences in Stress
Vulnerability
Watch: Can Yoga or Meditation Help
You Relax?
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Acknowledgments
Slide
Image Description
Image Source
template
lightning
©istockphoto.com/Soubrette
template
background texture
©istockphoto.com/Hedda Gjerpen
Ch17 image
Fear white knuckles
©istockphoto.com/Donald Macalister
3
book
©istockphoto.com/Carmen Martínez Banús
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
8
Figure 17.4
Pinel 8e, p. 446
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
17
Figure 17.9
Pinel 8e, p. 453
20
person reading books
©iStockphoto.com/Francesco Ridolfi
21
Figure 17.10
Pinel 8e, p. 455
22
white rat
©iStockphoto.com/Elena Butinova
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Acknowledgments
Slide
Image Description
Image Source
22
blue sky & clouds
©istockphoto.com/kertlis
23
medical clipboard
©istockphoto.com/Anastasia Pelikh
24
tabletop of stationery
©istockphoto.com/Stuart Burford
25
laughing
©istockphoto.com/Stratesigns, Inc.
26
Figure 17.2
Pinel 8e, p. 458
27
college age person coughing
©istockphoto.com/Sharon Barnes Photography
28
hand holding rat
©iStockphoto.com/sidsnapper
30
person thinking
©istockphoto.com/akurtz
31
toddler listening to adult speak
©istockphoto.com/Jani Bryson Studios, Inc.
32
crowd
©istockphoto.com/adisa
35
laptop
©istockphoto.com/CostinT
35
table and wall
©istockphoto.com/David Clark
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Pearson Education 2011