Mon Apr 10

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Mon Apr 10 Today only Lindseys office hours
begin at 200 (not 300)
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Early research/knowledge about the role of the
brain in emotion Removal of temporal lobe - tame,
passive, oral, hypersexual (monkeys Kluver-Bucy
Syndrome- 1939) Temporal lobe epilepsy
seizures often have intense fear as a prelude
aggression Removal of cortex
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History Remove cerebral cortex - get rage
response Decorticate rage Cortex appears to
inhibit/modulate emotional reactions. Allows for
cultural and higher cognitive influences on
emotion.
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IV. Brain centers relevant to emotion A. Limbic
System B. Cortex Many ideas come from studies
of brain-damaged individuals.
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A. Limbic System subcortical structures that
border around the thalamus Amygdala Hippocampus Hy
pothalamus Medial forebrain bundle
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• Limbic Structures - all are important
• Evidence now points to specific parts of
  temporal lobe relevant to emotions
• Amygdala
• Brain imaging studies show increased activity in
  amygdala when viewing fearful as compared to
  neutral faces and when viewing unpleasant vs
  pleasant stimuli
• People with phobias show activation of amygdala
  when exposed to their feared objects (spiders,
  snakes.)

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• Limbic Structures - all are important
• Evidence now points to specific part of temporal
  role relevant to fear the amygdala.
• Amygdala - fear recognition of facial emotions
  of others
• c. Human case studies of people with damage to
  the amygdala
• - difficulty identifying fearful or threatening
  facial expressions
• - difficulty identifying fearful or angry sounds
• - indiscrimately rate photos of strangers as
  trustworthy and approachable (normals do so for
  familiar people only)

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• Limbic Structures - all are important
• Amygdala - fear recognition of facial emotions
  of others
• d. Amygdala important for emotional learning and
  fear-conditioning.
• Conditioned fear responses - occur without
  involvement of cortex, but require the amygdala
  (current work by LeDoux)
• Sensory systems -gt thalamus -gt amygdala (then to
  cortex)

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• Limbic Structures
• Amygdala
• d. Fear conditioning pair a neutral stimulus
  with an aversive stimulus (shock loud noise)
  then fear the neutral stimulus (same
  physiological response)
• In context of fear, startle responses are
  increased. (in lab, if looking at pleasant
  stimuli, startle is decreased)
• Amygdala helps prepare the body for actions that
  would be necessary to respond to a threat.
• People with damage to amygdala can learn the
  pairing between stimuli, but the physiological
  conditioning does not occur.

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Limbic Structures e. Emotional intensity
facilitates memory of an event PET studies
better memory for emotional vs non-emotional film
clips is correlated with glucose utilization rate
in in right amygdala in normal subjects In people
with damage to amygdala, no memory facilitation
seen.
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• Limbic Structures
• 1. Amygdala
• e. recognition of facial emotions of others
• - particular importance to primary emotions -
  those shared by all humans and possibly
  vertebrates as well
• Fear, Sadness, Disgust, Surprise, Anger,
  Happiness

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• Biological programming of facial expression of
  emotion
• Paul Ekman - facial expression of emotion
• 1970s research in people of many cultures -
  studies in the Fore (New Guinea)
• across cultures - 6 core recognizable facial
  emotional expressions
• Anger Happiness Fear
• Disgust Sadness Surprise

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• Limbic Structures
• Amygdala
• Hippocampus puts conditioned fears in
  appropriate context
• If you get mugged along a particular route, you
  develop a conditioned fear to stimuli associated
  with mugger (gun, face, voice) amygdala does
  that.
• Development of a fear to the route itself and
  future avoidance of it is mediated by the
  hippocampus. Makes fears location-specific.
• In PTSD, these boundaries are lost. (Hear a
  plane fly overhead in their driveway, dive for
  cover). PTSD is accompanied by hippocampal
  damage/dysfunction in response to large and
  prolonged doses of stress hormones.

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• Limbic Structures
• Amygdala fearful stimuli
• Hippocampus related context
• Hypothalamus mediates the autonomic arousal
  associated with many emotional states (heart rate
  inc, facial flushing, stress hormone release,
  etc)
• helps coordinate the physical events necessary
  to take action fight or flight reactions
• Hypothalamus and amygdala have many connective
  pathways.
• 4. Medial forebrain bundle - midbrain to
  hypothalamus.
• Pleasure - electrical brain stimulation studies
  (self-stimulation)
• Dopamine is important neurotransmitter.

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Brain centers relevant to emotion A. Limbic
Structures B. Cortex 1. Prefrontal cortex 2.
Insula 3. Parietal Cortex

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• Prefrontal Cortex (when rest intact)
• Extensive connectivity between limbic structures
  and prefrontal cortex pathways mostly one way
  so hard to cognitively control strong emotions
• Orbitofrontal cortex (OFC)
• Provides updated info. to the amygdala that
  allows the extinction of fear conditioning
• Evaluates reward and punishment contingencies in
  specific place and time situational
  appropriateness of behavior
• People with damage to OFC show impaired ability
  to adapt when contingencies change impulsive,
  persistent, difficulty with reversal learning.
  Socially inappropriate may openly discuss very
  personal things or blurt them out in a group no
  social censoring of behaviors

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• Prefrontal Cortex (when rest intact)
• Extensive connectivity between limbic structures
  and prefrontal cortex
• Orbitofrontal cortex (OFC)
• b. Dorsolateral region of the prefrontal cortex
• Positive, pleasant, approach states are
  associated with greater left side activation.
  Expression of positive emotions controlled by
  left side.
• Unpleasant states, emotions, show more activation
  on the right side. Expression of negative
  emotions controlled by right side.
• Damage right (remove negative) gtgt may produce
  pathological laughter (cheerful manic)
• Damage left gtgt pathological crying (depressed))

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c. Assymmetries in prefrontal activity and
emotion Left side of face more emotionally
expressive than the right. Right hemisphere
better at controlling expression. Right
hemisphere also better at interpreting facial
emotion. General idea is that right hemisphere
is dominant for emotional expression. Left -
positive emotions Right - negative emotions, but
also integration and control of expression.

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• Brain centers relevant to emotion
• A. Limbic Structures
• B. Cortex
• 1. Prefrontal cortex
• 2. Insula-area of cortex that is tucked deep
  inside the Sylvian fissure
• appears relevant to processing the positive
  emotional aspects of eating
• PET scans show that it lights up when eating
  chocolate and foods that are craved
  

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Brain centers relevant to emotion A. Limbic
Structures B. Cortex 1. Prefrontal cortex 2.
Insula 3. Parietal cortex processing of
non-verbal expressions of emotion

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Brain centers relevant to emotion A. Limbic
Structures B. Cortex 3. Parietal cortex
processing of non-verbal expressions of emotion
(especially right parietal) Emotional tone of
voice Nonspeech sounds screams shrieks
laughing, crying Emotional faces Emotional
content of visual scenes