week 9 - long term memory - amnesia Flashcards
disconnecting explicit and implicit memory
amnesia=
term for loss of memory
disconnecting explicit and implicit memory
amnesia caused by:
actue virus infection that effects brain
parkinsons disease
brain resection as treatment for epliepsy
physcial accident
korsakov syndrome
even psychological
dissociating memory circuits
patient HM
what
scoville performed a bilateral medial temporal lobe resection of HM
seizures originated in teh region that includes the amagdala, hippocampal formation, and associated subcortical structures
so scoville removed them bilaterally
dissociating memory circuits
patient HM
breakthrough in understanding?
bilateral medial temporal lobe resection
results in sever and selective impairment in episodic memory
dissociating memory circuits
patient HM
not just hippocampus
EC entorhinal cortex
MMn medial mammillary nucleus
A amgydala
H hippocampus
CS collateral sulus
PR peirihinal cortex
structure of LTM
info from amnesia patients
disconnecting explicit memory
following the surgery HM suffered from severe emnesia
- could not recall anything that has happened after the surgery (no explicit memory)
despite this deficit HM has an above average IQ, he performed well on perceptual tests and he could still recall events from his childhood
HM performance on implicit memory tests left intact
Patient HM
what was intact?
memory for new skills
- but explicit memory for learning these new skills is impaired
- therefore repeated items show a smaller improvement
- STM intact
Patient HM
what was intact?
test
memory normal for motor learning (mirror drawing)
—> though no memory of having done the task before
so intact implicit memory
other amnesia patients
what was intact
tests
acquisition of various skills were found to be essentially normal in other amnesic patients
eg. towers of hanoi, mirror reading, pursuit rotor tasks (keep pointer on a rotating spot)
Patient HM
what was impaired?
memory for new personal events
memory for new facts
anterograde amnesia –> forgets everything new after few minutes
disconnecting implicit memory
double dissociation?
strong evidence of independent proceses
eg. implicit memory intact / explicit impaired
implicit impaired / explicit intact
disconnecting implicit memory
patient JK
impaired implicit memory with intact explicit memory
- developed parkinsons disease in his mid 70s and started to have memory problems at 78
disconnecting implicit memory
patient JK
damage?
to basal ganglia
disconnecting implicit memory
patient JK
impairment?
impaired abiliity to perform tasks that he had done his whole life
- eg. turning off the radio
disconnecting implicit memory
patient JK
intact?
could still recall explicit events
