Lecture 12: Memory & Amnesia Flashcards
Multiple Memory Theory
the idea that we have a number of different kinds of memory, each of which is dependent on different neural structures
Anterograde Amnesia
inability to acquire new memories subsequent to a disturbance such as head injury, electroconvulsive shock, or certain degenerative diseases
Retrograde Amnesia
an inability to remember events that took place before the onset of amnesia
Time-Dependent Amnesia
amnesia that is typically induced by traumatic brain injury, the severity of which determines how far back in time the amnesia extends, from the present to the more-distant past and generally shrinking over time, often leaving a residual amnesia of only a few seconds to a minutes for events immediately preceding the injury
Childhood (Infantile) Amnesia
an inability to remember events from infancy or early childhood
Fugue State
a sudden, usually transient, memory loss of personal history accompanied by abrupt departure from home and assumption of a new identity
Explicit Memory
a memory in which a participant can retrieve an item and indicate that he or she knows the item (i.e. conscious memory)
conscious, intentional remembering of events, facts, and personal experiences (episodic memories) that depends on conceptually driven, top-down processing in which a person reorganizes the data to store it
Episodic (Autobiographical) Memory
memory of life experiences that is centered on the person him- or herself
a person’s recall of singular events that enables human beings to remember personal experiences
Autonoetic Awareness
awareness of one’s self, or self-knowledge
Uncinate Fasciculus
a fiber pathway connecting temporal and frontal cortices
a hooked or curved tract
Semantic Memory
a memory of world knowledge stored independently of the time and place at which it was acquired
Ammon’s Horn
a region of the hippocampal formation named for the mythological horn of plenty
Dentate Gyrus
the region of the hippocampal formation
Granule Cells
sensory cells of the hippocampus
neurons that are round in appearance
Perforant Pathway
a pathway that connects (“perforates”) the hippocampus to medical temporal (limbic) regions
when disrupted, results in major hippocampal dysfunction
Fimbria Fornix
a pathway that connects the hippocampus to the thalamus, prefrontal cortex, basil ganglia, and hypothalamus
Entorhinal Cortex
cortex on the medial surface of the temporal lobe that provides a major route for neocortical input to the hippocampal formation
often shows degeneration in Alzheimer disease
Implicit Memory
a nonconscious and nonintentional memory of learned skills, conditioned reactions, and events
Priming
an experimental technique that involves using a stimulus to sensitive the nervous system to a later presentation of the same or a similar stimulus
Depth-of-Processing Effect
an improvement in subsequent recall of an object that a person has given thought to (in terms of, e.g. its meaning or shape)
Study-Test Modality Shift
the process by which people, when presented with information in one modality (reading) and tested in another modality (aurally), display poorer performance than when they are instructed and tested in the same modality
Huntington Disease
a hereditary disorder characterized by chorea (ceaseless, involuntary jerky movements) and progressive dementia, ending in death
Classical (Pavlovian) Conditioning
a form of nonconscious learning in which a neutral stimulus is paired with a stimulus that evokes behavior
Emotional Memory
a memory for the affective properties of stimuli or events that is arousing, vivid, and available on prompting
Fear Conditioning
a form of learning in which a noxious stimulus is paired with a neutral stimulus to elicit an emotional response
Panic Disorder
a disorder characterized by recurrent attacks of intense terror that arise without warning and without any apparent relationship to external circumstances
Short-Term Memory
a system for holding a neural record of recent events and their order used to recall sensory events, movements, and cognitive information such as digits, words, names, or other items for a brief period
Proactive Interference
interference of something already experienced with the learning of new information
Synesthesia
sensory mixing
the ability to perceive a stimulus of one sense as the sensation of a different sense
literally, “feeling together”
What are the multiple memory systems?
different kinds of learning and memory use independent neural processes
What are the components of long-term memory?
explicit (conscious)
implicit (unconscious)
emotional (conscious and unconsicous)
What is explicit memory?
episodic: personal, autobiographical
semantic: facts, knowledge
What is implicit memory?
skills, habits, priming, conditioning
What is emotional memory?
attraction, avoidance, fear
What is short-term memory?
sensory, motor, cognitive
~15 seconds, needs rehearsal to keep info active and in there; if something interrupts it, the info is lost
What is amnesia?
parietal or total loss of memory - resulting from localized brain lesions
What is working memory?
special case of STM requiring active manipulation of STM contents
What three stages does memory function rely on?
encoding learning: study processes
“storage” consolidation: rehearsal, re-encoding?
retrieval memory
Who was H.M.?
bilateral transection of temporal lobes
after surgery, left with anterograde amnesia; some retrograde amnesia
above average IQ
good memory for events before surgery, but unable to describe job he has worked for 6 months
good spatial memory for his immediate surroundings
What is anterograde amnesia?
inability to acquire new memories
What is global anterograde amnesia, like shown in the case of H.M.?
impairment in ability to form new memories across a variety of areas (e.g., spatial, semantic)
applies forward from point of trauma
not specific to one sensory system
What is retrograde amnesia?
inability to remember old memories
What is Korsakoff’s syndrome?
various types of brain damage related to chronic alcoholism
What is infantile amnesia?
loss of memory for the early years of life
What is transient global amnesia?
sudden onset, acute, and short course
loss of old memories and inability to form new memories
concussion, epilepsy, migraine, hypoglycemia
What is memory loss during ECT (electroconvulsive shock therapy)?
treatment for depression
can produce a transient amnesia: for a short time they experience a loss of memory
What was the Squire & Cohen (1979) experiment regarding ECT and details about TV shows?
recalling details about popular TV shows that aired for only one season
temporally limited retrograde amnesia in 20 patients
before ECT: most recent memories, a lot of facts recalled
after ECT: real detriment is in the details of most recent shows
most recent memories are not as strongly consolidated as memories made a long time ago
What is Ribot’s Law?
close to post injury is where memory deficit is worst
5 months: gross disturbance of memory back to infancy, RA total (2 years), AA total (not fixed)
8 months: recovery of memories from childhood, RA partial (4 years patchy memory), RA total (1 year), AA total (3 months), a few new memories recalled
16 months: memory for past events normal, RA total (2 weeks), AA total (3.5 months), new memory precise
after 16 months: 23 weeks residual permanent memory loss
What are the symptoms of Korsakoff’s syndrome?
anterograde amnesia
retrograde amnesia
confabulation
meager content in conversation
lack of insight
apathy
What are the areas of damage in Korsakoff’s syndrome?
caused by thiamine (vitamin B1) deficiency
damage may be in medial thalamus, mammillary bodies of hypothalamus, and general atrophy
most patients available for testing
What was the experiment involving recognizing famous faces over time?
three groups: nonalcoholic control individuals, alcoholic control individuals, patients with Korsakoff’s amnesia
gave pictures of same person across different decades
nonalcoholic patients: do pretty well
alcoholic patients: degradation on memory of most recent pictures, on their way to developing Korsakoff’s
Korsakoff’s patients: do worse on new info, do better on old
conclusion: mammillary bodies will not recover, deterioration will stop if they stop drinking and change diet, will prevent further deficit from occurring
What is auditory-verbal working memory?
phonological store
input buffer
output buffer
What is visual-nonverbal working memory?
visuospatial scratchpad
dorsolateral prefrontal cortex (DLPFC): receives info from parietal
What is the experiment involving the delayed response paradigm and monkeys with DLPFC bilateral lesions?
DLPFC bilateral lesion
food - screen, delay of 1-10s
put food in front of drawers, show monkeys where food is, then put up screen to block view of drawers
after even 1 second delay, lesioned monkeys will perform at chance levels, don’t remember, can’t hold position of food in store
when DLPFC is intact, the monkey will remember where food is
DLPFC: extension of dorsal pathway, strong for visual information
What is the single cell DLPFC experiment involving monkeys?
the monkey fixes its gaze on the X
after the stimulus (S) disappears the monkey must maintain fixation for a few seconds
finally, it must look to the spatial location where the stimulus had been
What is the relationship between the DLPFC and spatial location?
find cells that are specific to locations in the visual field
ventral lateral PFC may code for objects
What were the results of the meta-analysis of PET and fMRI scans on spatial and object memory?
spatial location: more dorsal activation
object recognition: more ventral activation
How was working memory spared in the case of H.M.?
spared ability to hold small amounts of information over brief periods of time
without hippocampal regions, there is only no consolidation of memory
Is the digit span task spared in cases of amnesia?
presented with 7 digits (1634589), have to repeat them back
was able to do immediate recall, working off short term memory, working memory is intact
Is the extended digit span task spared in cases of amnesia?
7 + n task (1634589 + 8; + 2; …), like the game Simon, will add on one more every time
rehearsal consolidates it to LTM
H.M. is capped at short term memory, so did not complete the task
Is the delayed non-match-to-sample task spared in cases of amnesia?
tested in monkeys with lesioned hippocampus
move eye toward the object that is not the same as sample
if it’s in short-term memory, they’ll do fine
< 10 second delay: correct
> 10 second delay: not correct, they have gone beyond capacity of STM
Is skill learning spared in cases of amnesia?
practice effects, or more general skill learning?: tested using the mirror reading task
some lines were repeated and one lines were not
patient with amnesia does not remember having done the task in the past, but they show improvement
if they are actually learning a new skill, they’ll get better over time no matter if it repeats or not
improvement on novel lines suggests there are practice effects but they do improve over time
How does the mirror drawing task show intact skill learning in patients with amnesia?
first time: draw out of the lines more often, over time they get better at the task
brain and body get used to the task
H.M. got better at the task but could not remember having done it; deficit in explicit, fine in implicit
How was repetition priming tested in cases of amnesia using the Gollin incomplete pictures task?
benefits from previous exposure
when shown the figures again after a delay, intact people recognize the objects at a less complete stage than initially, indicating that prior exposure influences performance
this same effect was shown in patients with amnesia, don’t have recollection of having seen it before, but have implicit memory
How did amnesia patients complete the stem completion task?
given a word list to memorize
then after delay given stems of words, tasked to fill in the word with whatever comes to mind
initial word list influenced their choice of words, will implicitly fill in the words even though they don’t explicitly remember the first word list
What were the deficits H.M. showed in learning new words?
hippocampal damage and semantic memory
was not able to learn new words
