lecture 8 Flashcards
threat conditioning
key empirical tool for studying how the brain Kearns to organise responses to danger and threats
auditory threat conditioning circuitry
auditory receptors transmit signals to neurons in the brainstem auditory nuclei
for learning to take place
signals evoked by the two stimuli need to be brought together
CS and US converges into the
amygdala specifically the lateral nuclei - LA
LA sends signals to the
central nucleus
central nucleus sends signals to regions that
generate responses
CG, LG, PVH
CG
Central grey area generates freezing
LG
lateral hypothalamus generates autonomic responses
PVH
paraventricular hypothalamus generates endocrine response
LA is where
CS and US information is brought together - possible site for changes in synaptic strength - memory
LA damage
prevents CR acquisition - unable to detect relationship
LA is the major site of
learning and memory in threat conditioning
amygdala is activated when a
person is unaware of the threatening stimulus
amnesic patients
damaged hippocampus
CR’S acquired but no declarative memory
hippocampus intact but amygdala damaged
CR’s not acquired but there is declarative memory
amygdalae are not
responsible for generating emotional feelings
feelings must be generated in the cerebra Cortex
what role does the cortex play in threat conditioning
sensory cortical areas are important for fine discriminations between CS’S
subcortical circuit is responsible for
quick responses to threatening stimuli
sensory cortex responsible for
discrimination between stimuli of similar type
amygdala is the primary site of the
learned changes that result from threat conditioning
hippocampus is critical for
contextual learning - learning about CS-US contingency
threat conditioning occurs in a particular context associated with the
aversive US
contextual cues alone can
evoke CR’s
contextual effects are reduced/absent if the hippocampus
is damaged- hippocampal input to the amygdala
cortex is responsible for
feelings - feelings of fear are elicited by CS’s following training
extinction does not
erase prior learning
inhibitory pathway is activated - both acquisition and retention requires the cortex
subcortical circuit acts quickly to put the body in a state of
readiness to deal with upcoming danger
cortical components
slow with discriminate / identification ability - determine whether the response is worth responding to
functionally specialised
regions are duplicated in the two halves and serve the same function
functional localisation
if a particular function is carried our only in one specific region
functional lateralisation
particular function is carried out in one side of the CNS but not in the other