Affect and Emotion 1

A useful analogy

sensations => affect => emotions

dimensions of affect

valence

arousal activation intensity

valence

positive vs. negative

approach vs. avoid

goal-conduciveness

arousal activation intensity

high, medium, low activation

phineas gage

accident destroyed parts of medial frontal cortex

survived but changed personality. couldn’t hold down job, became vulgar, impulsive, and temperamental

cats displayed normal emotional reactions to dogs after severing

sympathetic afferents from the body

cats displayed exacerbated responses to benign stimuli (sham rage) after

removing full neocortex, but not when thalamus/midbrain included

stimulation of hypothalamic regions can produce

similar defensive behaviors or the desire for further stimulation

papez circuit

control memory and emotions

kluver-bucy syndrome

monkeys with temporal lobectomy were:

less emotionally reactive

less reactive to novelty/exploration

hyperoral/hyperphagic

removal of amygdalae was sufficient to obtain symptoms of

kluver-bucy syndrome

reptilian brain (basal ganglia)

primitive surivival-related emotions (e.g., fear, aggresion); reflexive

visceral/paleomammalian brain

aka limbic system

integrates sensory, bodily signals

elaborated emotions, learning

neomammalian brain (neocortex)

abstract thought, prospecion, reasoning

emotion-cognition interface

regulation of emotions

the limbic system

includes papez circuit

hypo/thalamus, cingulate, hippocampus

adds regions such as amygdala, insula, ventral PFC

James-Lange theory

stimulus => autonomic response => behavioral response => emotion

Cannon-Bard theory

stimulus => central response => autonomic response AND emotion

Schacter’s theory

proposes that emotions are a result of two key components: physiological arousal and cognitive interpretation

temporal distinctions in reward processing

Reward unfolds over time in two key phases:

• Anticipatory (appetitive): before the reward occurs — the desire, expectation, or craving.

• Consummatory (experienced): after receiving the reward — the pleasure or satisfaction of consuming it.

functional distinctions in reward processing

Each phase can be linked to a specific function:

• Wanting: the motivational drive to obtain a reward (e.g., craving, effort to get chocolate).

• Liking: the actual pleasure from experiencing the reward (e.g., enjoying the chocolate).

• Learning: using past rewards to predict future outcomes (e.g., remembering that chocolate is good).

These are not always aligned — for instance, people with addiction might "want" a drug intensely without "liking" it as much anymore.

neural evidence of wanting

linked to dopamine systems, especially in the ventral pallidum (VP)

Dopamine increases wanting but doesn’t necessarily increase liking.

neural evidence of liking

involves opioid systems and more localized "hedonic hotspots" in the brain.

opiod stimulant enhances liking

reward/pleasure circuits

wide and distributed set of regions associated with wanting

hedonic hotspots

narrower subset of reward/pleasure circuits linked to liking

defensive responses to potential threats (e.g., flight, freeze, flee) are determined by

the predator proximity, and possibility of escape

and shaped by ecological nice

the amygdala is critical for mediating

innate and learned associations between stimuli and appropriate behavioral programs (e.g., defensive freezing)

avoidant behavior in rats

Amg or PAG stim generates avoidance

SM & personal space

patient with amg lesion needed less personal space between her and experimenter

generalization of aversive associations

After learning that a certain stimulus (like a tone or image) predicts something negative (like a shock), people and animals often:

• Respond fearfully not only to that exact stimulus (called the CS+, or conditioned stimulus),

• But also to similar but new stimuli (generalization stimuli, GSs).

brain regions that selectively track positive outcomes

vMPFC Str

Positive > Negative Affect

brain regions that selectively track negative outcomes

dMPFC Amyg Ant. Insula

Negative > Positive Affect

Insula lesions impair

learning from losses, leave gain learning intact

amygdala lesions exhibit

no/reversed loss aversion during risky choice