lecture 2 Flashcards
hippocampus is a key
region in anterograde amnesia
damage to hippocampus results in
long term declarative memory formation impaired
korsakoffs syndrome
caused by thiamine deficiency as a result of long term alcohol abuse results in amnesia
amnesics are able to acquire
CR’s
eye blink conditioning experiement
subjects sat watching a movie whilst exposed to a tone then air puff
delay conditioning
who took part in the eye blink conditioning experiment
normal controls and a group of anterograde amnesics with hippocampal damage
results of eye blink conditioning
normal participants and amnesics acquired CR’S
but no amnesics formed a declarative memory of having undergone the procedure
but some normal controls did
not notice the CS-US relationship
trace conditioning
short beep then no stimulus then air puff
results of trace conditioning
amnesics failed to acquire CR’S
rat experiment
removal of hippocampus prior to conditioning - CR’S acquired if delay procedure is used but not the trace conditioning
what is needed for trace conditioning
hippocampus retains info about the CS over trace interval
if so- CR’s acquired before hippocampal removal should not be affected
stored memories are
not lost only the capacity to form new ones
hippocampus is crucial for
holding info overtime during acquisition of long term memories
hippocampus is Not involved in
delay conditioning but similar structure playing a similar role is the cerebral cortex
if the cerebella cortex is damaged
cr acquisition is no longer possible
If structures involved in acquisition are damaged
new long term memories cannot be stored - anterograde amnesia
if structs involved in retention are damaged
old memories are lost- retrograde amnesia
hippocampus is important for forming
new memories but not for storing them
delay conditioning does not require the
hippocampus
forgetting In long term non declarative emory is much
less common eg- can’t forget how to ride a bike
unlearning
undoing the effects of prior learning - where memory is non declarative
reasons to undo learning
sport
get rid of phobias
two ways of actively undoing the effects of learning
erasure and suppression
erase
erase the memory
suppression
suppress the memory
reversal of habituation
dishabituation undoes the effects of short term habituation
can the effects of pavlovian conditioning be undone
trainee learns to respond in an anticipatory manner(CR) due to the fact that a CS signals the occurrence of a US
what procedure tests whether the trainee can learn to stop responding to the CS in an anticipatory fashion
phase 1 - training with forward conditioning protocol - CS is paired with US until learner acquires CR
phase 2 - exposure to a sequence of presentations of the same CS without US
example of procedure
CS=Tone US= food delivered UR= poke of nose CR= poke of nose gradually rat learns not to respond to poke its nose when it repeatedly hears a beep
procedure that follows conditioning and involves presenting the CS without US is called an
extinction procedure
does extinction procedure ERASE the memories or SUPPRESSION of CR
no
spontaneous recovery , renewal, reinstatement
spontaneous recovery
condition = CS then US
extinction = CS without US
Delay and test = CS only
behaviour comes back - has not completely disappeared
recovery tends to be greater for
longer intervals
renewal
subject is conditioned in one context A
then transferred to a different context B
extinction procedure administered
after extinction transferred back to context A or new one
extinction procedure
presenting CS without US
renewal effect
back in context A animal is tested with CS alone - CR is present
reinstatement
following extinction , the subject Is presented with an aversive US
CS elicits CR
example of reinstatement procedure
CS= Tone US= foot shock
extinction - repeated presentation of the tone CS without the shock until the CR disappears
Following extinction the shock US
is presented alone a few times and when the CS is presented alone, CR elicited once agin - reinstated
exposure therapy
used for the treatment of phobias - may not remove the cause
new learning that counteracts the effects of prior learning
inhibitory stimulus response connection
conditional reflex pathway is intact but an inhibitory pathway is formed as a result of extinction which
prevents CR from occurring
why suppress rather than erase
extinction is context sensitive - renewal and reinstatement
not completely lost but is available in contexts where its still useful
