ch15 - emotions: neural mechanisms of fear and motivation

we’re now looking at the second aspect of emotion which is….

actions!

pavlovian classical conditioning

1. tone CS (condition stimulus) presentation prior to conditioning

2. conditioning (CS-US pairing)

3. CS presentation (after pairing)

fear conditioning requires the ____

amygdala

click to reveal the amygdala/fear diagram👀

sensory info about threat is conveyed to ____ of amygdala

lateral nucleus

info flow of threat in amygdala

LN → CA (central amygdala) → PAG → LH → avBST and PVH

LN (lateral nucleus)

sensory info about threat

CA (central amygdala)

output to structures

PAG

petiaqueductal gray; defensive behavior (like freezing)

LH (lateral hypothalamus)

autonomic activation (involuntary functions)

avBST and PVH

bed nucleus/ paraventricular: release stress hormones

amygdala activated under these emotional contexts (5):

• threatening faces

• frightening situations

• disturbing scenes

• people of other races (hostility/fear)

• anxiety-like conditions

what are the four aspects of emotion again!

1. physiological (autonomic)

2. actions

3. motivation (approach/avoidance)

4. feelings

is hypothalamus singularly important for emotional expression?

nope!

info relevant to _____ (like fear-related freezing) exists amygdala, may bypass _____ and project directly to the ___ and others to produce ___ responses.

emotional behavior/ hypothalamus/ PAG/ behavioral

third aspect of emotion

motivation!

amygdala actually has an important role in ____ emotional states

negative

olds and milner’s landmark finding

brain self-stimulation (targeted LH accidentally)

in order for a brain to self-stimulate, you activate the _____ pathway.

medial forebrain bundle

medial forebrain bundle (pathway)

contains dopamine neurons from the VTA that inner age nucleus accumbens

pleasurable experiences involve ____ activation

dopamine-nucleus accumbens pathway

VTA-DA neurons play a role in ______

reward prediction error (fire more AP when it’s higher than expected, vice versa)

key to relationship between experience and consequences

VTA-DA, reward prediction error and AP firing