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