Emotion

Bilateral Amygdala Damage

afraid rating very low intensity

Actually a good artist, drawing for afraid is of a baby - confusing

• Basic emotions: There are core basic emotions that all humans can experience (Darwin)
• Ex: Paul Ekman's universal facial expressions: angry, happy, disgust, surprise, sad, fear

• Dimensions of emotion: emotions are not discrete states, but vary along a continuum
• 1. Valence vs. Arousal
• 2. Approach vs. Withdrawal

• Valence (good, bad, or pleasant, unpleasant) vs. Arousal (high or low intensity)
• Ex: find penny on street: positive valence, low arousal
• win lotter: positive valence, high arousal

• define emotions by the goals they motivate: do they cause one to approach or withdraw from a stimulus?
• not the same as positive or negative (anger is a negative state that motivates one to approach)

• Mood induction
• Reward or punishment
• Emotionally evocative stimuli

present emotional stimuli (film clips) and encourage subjects to get in the mood

• reward subject with money or food
• punish subjects with shock or aversive sound

• words like "cancer" "love" or taboo words
• emotionally laden pictures
• -international affective picture system

• Direct assessment
• Indirect assessment

Just ask: how d you feel, how would you rate this stimulus

• Choosing among possible options: subjects choices reflect relative value placed on various options
• Facilitation or inhibition of a response: emotional stroop, automaticity of emotional processing
• Psychophysiological asessments: skind conductance, heart rate, startle eyeblink, pupil diameter

• Implicit Emotional Learning
• blue square paired with shock then illicits startle response and increased skin conductance

do not show fear response with skin conductance after the conditioned stimulus (blue box) but do show it with unconditioned stimulus (shock)

Instructed fear- every time you see the blue square you will get a shock (but you actually don't), but still increasess skin conductance

James Papez proposed circuit of neural structures involved in emotional processing: hypothalamus, anterior thalamus, cingulate gyrus, hippocampus

Maclean named structures Papez circuit and extended network to include amygdala, orbitofrontal cortex and basal ganglia

• 1. what is the criteria for a limbic structure?
• 2. some limbic regions though to be involved in emotion are now known to be more important for non-emotional behaviors like the hippocampus

Animal models

• Kluver-Bucy syndrome- monkeys don't avoid fearful stimuli
• neurons in amygdala respond to affective nature of stim
• amygdala critical for acquisition and expression of CR

• emotional memory
• evaluation of emotional stimuli
• implicit emotional learning
• explicit emotional learning
• modulates hippocampal consolidation

emotional words are remembered better than neutral ones after a delay

• semantic organization
• distinctiveness
• attention
• retention/post-stimulus elaboration
• retention/consolidation (differential forgetting curve for arousing events)

• Right and Left Temporal lobe lobectomy pts rated taboo and neutral words.
• SCR and verbal arousal ratings recorded
• No differnce with controls for rating and SCR
• However, immediate and delayed recall for taboo words: controls remembered more taboo words, and LTL remembered the least words AND least taboo words

alter amydgala function

Humans and animals w amygdala damage don't show increased autonomic arousal (SCR) when waiting for an aversive stimulus

amygdala is critical for the autonomic expression of a learned aversive response in fear conditioning

• Humans with amygdala damage can reporte that a CS can predict an aversive event in fear conditioning.
• (hippocampus -dependent)

• dissociation bw physiologicla expression of fear response (AMYGDALA DEPENDENT)
• and cognitive understanding of CS (HIPPOCAMPUS DEPENDENT)

• 12 healthy subjects presented:
• rest, safe (yellow square), threat (blue square)
• Increased SCR to threat and slight increase in safe in comparison to rest
• even though no shock is administered

• increased left amygdala activation in expectation of aversive stimulus (threat vs. safe condition)
• indicates the role of amygdala in explicit emotional learning

• With eye tracking, revealed that SM wasn't looking at the eyes.
• fear is particularly connected to the eyes

could ID fear comparable to the control group

• vary the degree of expressed emotiona and look at brain activation
• ex: manipulate the degree of disgust and correlate with ERP components

disgust face

Fusiform Gyrus

• neutral faces
• the more you deviate from a neutral affect face, the less neural signaling you get.
• a prototypical face generates the greatest N170 in the Fusiform Gyrus

• disgust face
• greatest neural component for the disgust face
• also activated when we experience disgust

• 1. fear: Amygdala: Learning, Avoidance
• 2. Anger: Prbitofronal Cortex, Anterior Cingulate Cortex, indicates social violations
• 3. Sadness: Amygdala, Right Temporal Lobe: withdraw
• 4. Disgust: Anterior Insula, Anterior Cingulate Cortex, Avoidance

no, it is not the only emotional substrate involved in emotion

our ability to perceive other emotions is tied to our ability to experience it ourselves- it evokes the same emotional processes

if we couldn;t experience disgust, could we still perceive it in other people?