Class 6 - Memory 2 Flashcards
Short-term memory
a storage capacity just after sensory memory
- Short duration: seconds to minutes
- Limited capacity: 7 ± 2 items – Miller’s digit test
Working memory
all definitions will involve the ongoing maintenance of information
(e.g. a group of components that hold in mind a limited amount of information temporarily in a heightened state of availability for use in ongoing information processing)
TB- limited capacity store for retaining information over the long term (matinetns) and for preforming mental operations on the contents of this store (manipulation)
esting STM / WM
Forward span test: repeat back 5 7 9 4 2 6 (STM - holding the digits in mind)
Backward span test: repeat that list backwards (WM - not only hold but also able to manipulate)
Dorsal lateral prefrontal cortex (DLPFC) neurons fire
during a delay period for a delayed match paradigm
stay active for as long as delay period is
activity in frontal and parietal regions together
could classify the
type of stimulus being held in mind
uncued stimulus shows a
reduction in representation, but is not gone forever
• So perhaps the level of activity in the PFC doesn’t correspond to maintaining the representation but maybe ongoing selection of what interested in
Deficits of STM / WM is usually tied to
information-processing system
Episodic memory
Contains information specific to the time and place of acquisition
(in delarative memory)
Semantic memory
Facts we know about the world without contextual information
(in delarative memory)
Quesonare Pic
D
Paitent KC
bilateral damage to hippocampus
could rember semantic but not episodic
Semantic dementia
(temporal variant of frontotemporal dementia)
- Damage to anterior temporal cortex
- Impaired semantic memory: knowledge of the world drastically impaired
- Spared episodic memory
How info is encoded in long term memory
what and where pathways
Subsequent memory effect
items that are remembered during recall are associated with more activity at encoding
• Medial temporal lobe (MTL) is involved in successful encoding
Remember/know paradigm
tese where have a specicfic memory vs general idea
rember when vs know that
Remember
– can remember personal episode related to the subject
Know
have knowledge of what subject is but no specific episodes
Hippocampal damage as a baby
Some personal events he could remember, others he only knew about • Greater activation of residual hippocampus when retrieving ‘remembered’ events versus ‘known’ events
more hippocampal activity for __ compired to familarity
also at ___ only when correctly __
recolection compaired to familarity
also at retreval only when correctly retreave
High conficance that (ex. I saw this word)
a sence of filmarity
actitivy in pererrhinal cortex related to how confident something was there
Consolidation hypothesis
- When just encoded, memories are dependent on hippocampus for retrieval
- After a while, they become ‘consolidated’ or independent of the MTL (or hippocampus), instead dependent on cortex
- This explains commonly observed temporal gradients: information not yet consolidated cannot be retrieved once hippocampus is damaged
Multiple trace theory / Transformation hypothesis
- Hippocampus important in retrieval of truly episodic memories
- Explains flat retrograde amnesia
- How can this explain commonly observed temporal gradient? • Older episodic memories become ‘semanticized’ and no longer need the hippocampus for retrieval
Dementia
an umbrella term for the loss of cognitive function in different domains (including memory) beyond what is expected in normal aging.
most common types of dementia are
irreversable
and are the result of neurodegenerative disease, vascular disease, or a combination of the two
alzhimers contributes to __ of dementia deseses
60-70%
Alzhimers is chartarized by the
extracellular deposition of aggregated beta-amaloid protines and the intracellular accumalation of neurofibulary tangles
beta-amaloid protines
negatively affecting synapse formation and neuroplasticity
neurofibulary tangles
aggregations of microtubules associated with hyper-phosphorylated tau protein.
Pathology of Alzhimers
first medial tempral lobe structres are affected
second extends to lateral temporal, perietal, and prontal neuocortices
Second most common type of dementia
Vascular dementia
decreased oxygenation of neual tissue and cell death resulting from ischemis or hemorrhagi infracts, ruptures of small vesicles
50% of Alzhimers mixed with this
sensory meory
transient retention of sensory information in sensory structures
echotic memory
hearing sensory memory
isonic memory
visual sensory memory
how sensory memory is mesured
mismach negativity MMN (electrical)
mismach field MMF (magentic)
when impurs differ MMN and MMF are genrated
Modal Model
information is first stored in sensory memory then iteems selected by attetional processes can move to short term storage and if it is rehersed it goes to long term storage.
At each stage of the modal model information can be lost by
decay
interference
or a combination
Demonstrated that short term memory is not the gateway to long term memory
KF and EE
KF- damage to L perisylvian cortex, reduced diget span, retained ability to form certine types of new long term memories lasting more than a few seconds
EE- tumor in L agnular gyrus, after removal, below normal short term memory but preserved long term memory
Three part working memory system consits of
a central executive mechanism - presides over and cordinates interactions between two subcordinate short term memory stores (phenomonlgical loop and visualspatial sketchpad) and long term memory
Phonological loop
propsed mechanism for acustacly coding information in WM, is modality specific
Visualspatal sketchpad
short term memory store that paralls the phonological loop and permits information storage in either purly visaul or visualspatial codes
lesions of left supramarginal gyrus have deficits in
phonologcal working memory
cannot hold strings of words in working memory
noncelarative memory
implicit memory
procedural memory
required for tasks that include learning motor skills
depends on extesive and repeated experence
Priming
type of nondeclarative memory
change in the response to a stimulus or in the ability to identify a stimulus folowing prior exposeure to that simulus
Preceptual priming acts within the
perceptial representation system (PRS)
- within this the structure and form of objects and words can be primed
Word priming effects dissapear within ___
two hours
much longer effects are seen when pictures are the simulus, these are reliably found at 48 weeks
PRS does not rely on
the medial temporal lobe
Damage to the hippocampus does not impair __ conditioning but does imapir __ conditioning
delay
trace
Habbituation
response to an unchaning stimulus decreases over time
Sensatization
response increases with repeated presentations of the stimulus
__ is actavated when information is correctly recalled
hippocampus
is not actavated with familaraity
___ are activated durring reconition based on familarity
left anterior medial parahippoampus gyrus
a regon that correspons to the perirhinal cortex
Binding problem
how the brain bundels all of of the information
involves where and what
Standard consolidation theroy
considers the neocortex to be crutial for the storage of fully consoladated long term meories where as the hippocampus plays only a temporary role
Multiple trace theory
sugests that long term sores or semantic information rely soly on the neocortex while episodic memory, wether consolidated or not, rely on the hippocampus for retreaval
