L13 - memory and amnesia Flashcards
capgras syndrome
delusion of imposter - assoc w psychoses, brain lesion
freud view: love mother, hate father, sexual desire repressed thru childhood, blow to head released = attraction to mother - so weird, must be imposter.
- familiarity & mood - resembles mother, no feeling of warmth. no galvanic skin response
what is amnesia?
partial or total loss of memory.
multiple memory systems - diff learning/mem use independent neural process
LTM - explicit: conscious = episodic = semantic -implicit: unconsious = skills, habits, priming, conditioning - emotional: conscious or unconscious = attraction, avoidance, fear
STM - sensory, motor, cognitive.
memory classified by CONTENT
declarative
non-declarative
declarative mem - where
explicit. facts, events
- medial temporal lobe, diencephalon.
non-declarative - what kind? where?
implicit skill/habits = striatum priming = neocortex classical conditioning - emotion : amygdala - skeletal musculature : cerebellum nonassociative = reflex pathway
memory classified by PROCESS
encoding = process of memory storage
retrieval = process of remembering
free recall: retrieval without aid of cues
cued recall: retrieval with cues
recognition: stimulus triggers remembering
memory classified by TIME
Sensory mem - iconic < 1 sec; echoic < 2 sec
STM = <15 sec, hold 7+/- units - is conscious and active *chunking put a hole in this
LTM - episodic, semantic, procedural. forever (if recalled regularly)
STM and LTM refer to temporal stages of memory
murdock’s big three - within episodic memory
memory for items
memory for associations
memory for order
memory for items
murdock’s big three
paradigms include: recognition,, free recall,
brain areas: hippocampus, entorhinal cortex, various neocortical areas
memory for associations
murdock’s big three
paradigms: classic paired associate learning (cued recall); associative recogntion
brain areas: hippocampus. (unless terms co-occur to point where theyre processes as one.
memory for order
paradigms: serial recall, judgements of relative recency
brain areas: if relational, hippocampus; evidence for PFC
memory function relies on three stages
- encoding learning
- storage, rehearsal, re-encoding
- retrieval memory probe process, memory search
HM - damage? symptoms?
bilateral trasection of temporal lobes
- global anterograde amnesia, partial retrograde amnesia.
- good spatial mem. small piece of hippocampus remained
3 types of amnesia - 2 + 1 syndrome assoc w
anterograde amnesia : inability to acquire new mems.
retrograde - inability to remember old mems - easier to remember older than newer ppast mems
korsakoff: brain damage assoc w chronic alcoholism.
varieties of amnesia
infantile amnesia fugue state transient global amnesia electroconvulsive shock therapy restricted brain damage = specific amnesia
infantile amnesia
loss of mem for early years of life. - brain cant encode and maintain mems when young
fugue state
mem loss - no knowledge of life.
transient global amnesia
sudden onset, acute, short course.
- loss of old mems, inability to form new mems.
- concussion, epilepsy, migraine, hypoglycemia
Electroconvulsice shock therapy
treatment for depression. can produce transient amnesia - lot of retrograde, some anterograde
restricted brain damage = specific amnesia
amnesia for verb, noun, animal. rare
ECT study
before = remember tv show thats closer in time
after ect = overall prformance decrease. greater deficit in early/mid-retrograde events.
temporal gradient of amnesia = ribot’s law
- time gradient in retrograde amnesia, recent mem more likely lost than more remote mems.
- encoding happening thru healing process - problem accessing when healing, but they’re encoding = once healed can be accesses
korsakoff’’s syndrome
characterization?
- cause
- damage?
anterograde amnesia, retrograde amnesia - confabulation meager content in convo lack of insight apathy - caused by lack of vit b1 - damage to medial thalamuc, mamillary bodies of hypothelamus, & general atrophy
recognizing famous faces over time
- non alcoholics - stronger recogntiion for later info. mid-point weakest, recent is present. recency & primacy effect.
- alcohol: mid-point btw nonalcoholics and korsakoff
- korsakoff - memory decreased overall, recent mem is worst. hippocampal dependent, altho hippocampus may not be damaged.
baddeley’s model of WM
3 part WM model.
- central executive: supervisory system, controls flow of info.primarily controlled by DLPFC
- slave systems: phonological loop ( stores verbal content) & visuo-spatial sketchpad (visuo-spatial data)
- two tasks at once = two separate perceptual domains - performance less efficient.
- phonological short term store: greater recall on most studied items.
delayed response paradigm
- lesion in DLPFC
monkey sees wells, 1 has food. with lesion - doesnt reach for correct well.
- fixate, maintain fixation as stimulus fires on other part of screen. when cued - look to spatial location. when record at DLPFC - neuron active to maintain representation of spatial location for 10 sec or less.
neuron specificity for direction
- specificity of d/v lobes.
maintain representation for readiness/awareness. need to know context.
dorsal frontal lobe = space; ventral frontal lobe = objects. fits w streams.
spared working memory in amnesia
HM - digit span task
monkey w lesion hippocampus
digit span = 7 digits = normal.
extended digit - 7+n. HM couldnt rehease, would maybe know last few digits.
- MONKEY: If delay is longer than 10 sec, random chance whether theyll guess correct answer.
spared skill learning
- mirror tracing, rotart pursuit
- practice effects? more gneral skill learning?
- draw in mirror, follow finger with moving object = normal presentation in amnesivs.
practice = better with repitiion. skill learning = better with more types of problems.
in amnesic, korsakoff & ECT - similar presentation as control
repitition priming in amnesia: repeated exposure.
more exposure to object - better able to recognize at lower/ less complete form. Practice learning effect.
- shown figures after delay - prior exposure influence performance: for amnesia and normal.
sternberg memory scanning: varied set
vs fixed set
5 digit shown. probed w number, ask if it was in first digits.
- more digits = longer to respond.
- search is exhaustive - probe in middle, rehearsal goes all the way to end. HM could perform. not a long delay
fixed: remember 5 digit from last task. recall from LTM. response time slower. HM couldnt remember
word-stem completion task
condition 1: cued recall
condition 2: implicit
present word list
condition1: recall words that start with same letters. amnesics dont do well.
condition2: first 3 letters of one of words shown - amnesic more likely to say words presented than normal.
eye movement - implicit task.
eye movement tracked. 3 objects in scene. eyes around each one.
change pic, 3 objects, one not in original spot.
normal: look at all three previous spots.
amnesics - dont look at spot where object was.
hippocampus engaged to remember where previous object was.
amnesics w hippocampal damage cant do. korsakoff patients - cant do.
HM deficits in learning new words
- maxed out on trials to learn new words.
- made a ton of errors
== no sign of learning
