psyc201 4

The amygdala processes

emotional salience - anything that matters, good or bad, ambiguous or threatening. especially fear and ambiguoius behaviours

basolateral nucleus (input) recieves

sensory information and processes it

Central nucleus (output)

sends signals to trigger fear responses — freezing, stress hormones, etc

The "low road"

thalamus → amygdala (fast, crude, automatic — you jump before you know why)

The "high road

thalamus → cortex → amygdala (slower, refined by thinking)

how the thalamus connects to amygdala

Receives raw sensory signals — enables fast automatic threat detection (low road)

how the PFC connects to amygdala

PFC normally inhibits the amygdala — regulates emotional reactions. Chronic stress impairs this. PFC-amygdala loop is central to emotion regulation

how the hippocampus connects to amygdala

Provides context — "is this situation actually dangerous?" Helps with fear extinction (learning something is no longer threatening)

how the hypothalamus connects to amygdala

Amygdala triggers the HPA axis → cortisol release; prepares body for action

Patient S.M.: had bilateral (both sides) amygdala damage

She felt no fear of snakes or dangerous situations, had difficulty recognising fear in others' faces, and avoided looking at eyes (key social signals).

Klüver-Bucy syndrome (monkeys): amygdala damage made monkeys

tame, fearless, and socially impaired — unable to recognise dominant/dangerous group members.

Toxoplasma gondii: a parasite that impairs amygdala-based fear responses in rodents

making them attracted to cat urine instead of avoiding it. Shows how "turning off" amygdala activity changes threat behaviour.

Hyperactive amygdala: some people have overactive amygdala responses, linked t0

anxiety, PTSD, and genetic variants like the SERT s-allele. Anxiety = amygdala on high alert for ambiguous "what ifs."

James-Lange theory

physiological changes come first, then we feel the emotion. (You see a bear, your heart races, therefore you feel fear — not the other way around.)

Constructed emotion theory (Lisa Feldman Barrett)

emotions are not fixed, built-in programs. The brain constructs them from bodily sensations + context + past experience. There are no universal "basic emotion" circuits.

Emotions are evolutionary functions so we have a ___ bias

Negativity bias (we notice bad things more) evolved because missing a threat was more costly than missing an opportunity.

testosterone facilitates…

aggression. Serotonin inhibits impulsive behaviour. Cortisol inhibits aggression. High testosterone + low cortisol = greatest predictor of aggression.

the ventromedial PFC integrates emotion with decision-making. Phineas Gage

lost vmPFC function and became impulsive and morally erratic.

chronic stress impairs the HPA axis which impairs

level of cortisol, leading to heightened vigilance and emotional reactivity

in many disorders that ___ phase is compromised

the anticipation phase, the liking phase isn't

MAOa gene

low activity form shows a link to aggression, but there needed to be moderate to severe childhood maltreatment

cognitive empathy

can't process that the other person is feeling

compassion fatigue

distressed when others are distressed

lower empathetic accuracy in…

text based communication