Chapter 11: Emotional Memory Systems Flashcards
What was the Papez (1937) circuit for emotional memory?
based on gross anatomical evidence
bunch of midline structures that have connections
internal loop that could manifest emotions, thought it was independent
What is Kluver-Bucy syndrome (1939)?
amygdala lesions and MTL tip
thought it might go beyond emotion, but its the para-hippocampal system
H.M. as evidence; different recall of emotions/experience
What was the MacLean (1949) circuit for emotional memory?
“limbic system”
Papez + amygdala, septum, PFC
cerebral cortex was the area that showed the most development, but amygdala was for feeling
added amygdala and part of prefrontal cortex to the circuit
How does the amygdala facilitate emotional memory?
integrates information from limbic and diencephalic areas
outputs to limbic and neo-cortices (memory related) as well as diencephalon
interposed between homeostatic and higher order structures; allows it to perform both conscious and unconscious actions
interface between internal/external signals; able to relate external stimuli to certain outcomes
What kinds of signals about sensory stimuli might the amygdala provide?
may provide “meaning” or relevance” signal concerning sensory stimuli
lesions blunt affective responses
memory processes affected include both declarative and procedural subtypes
emotional conditioning
What was the cued fear response experiment used to test the role of amygdala in memory in rats?
tone is played, then floor becomes electrified
bring animal to a new chamber, play the tone but don’t provide a shock, rats will freeze when scared, measure response
if they are brought back to the same room they will exhibit fear of the environment
What were the results of the cued fear response experiment used to test the role of amygdala in memory in rats?
both auditory thalamus AND auditory cortex lesions decrease cued fear response
lateral amygdala lesions decreased cued fear response
striatal lesions produced no effects
lateral amygdala lesions also decreased contextual fear
HPC lesions only affected contextual fear, not CFR
What was the potentiated startle response experiment used to test the role of amygdala in memory in rats?
condition animal; give a light, at the end of the light, floor becomes shocked
normal startle reflex: loud noise causes startle
potentiated startle: turn on light, then play loud noise
difference in intensity of startle will show how much the amygdala is involved
What is the lateral subnucleus in the amygdala?
input structure
What is the central-medial nucleus in the amygdala?
output structure
autonomic responses (hypothalamus and brain stem)
What is the basil nucleus in the amygdala?
both input and output structure
responding and remembering
What were the results of the potentiated startle response experiment used to test the role of amygdala in memory in rats?
lesions of L, BL, or C nuclei prevent conditioning and abolish expression of previously learned CSRs; modulate how much of the startle is expressed, no amplification
NMDA blockers in amygdala eliminate conditioning but don’t eliminate previously formed CSRs
How is the amygdala involved in the extinction of conditioned fear?
therapies for PTSD, phobia and anxiety; repeated stimuli exposure in absence of aversive consequence
role of PFC (Quirk): increase activity during extinction, activity decreases fear behavior, NMDA dependent, project to inhibitory ITC neurons
