10: The Remembering Brain 1 Flashcards
what are the 2 types of long-term memory?
declarative (explicit) & non-declarative (implicit)
what are the 2 types of declarative/explicit memory?
episodic & semantic
what are the 4 types of nondeclarative/implict memory?
procedural
perceptual representation system
classical conditioning
nonassociative learning
which 3 areas of the brain are associated with declarative memory?
medial temporal lobe
middle diencephalon
neocortex
what distinguishes autobiographical memory from episodic memory?
autobiographical memory encompasses both episodic and semantic memory
what are the 3 parts of the medial temporal lobe?
hippocampus
entorhinal cortex
para hippocampal gyrus
what are the 3 segments on the parahippocampal gyrus
rhinal sulcus, perirhinal cortex & parahippocampal cortex
what is the order of information flow within the medial temporal lobe?
perirhinal and parahippocampal cortex -> entorhinal cortex -> hippocampus
- all areas perform information processing
define: anterograde amnesia
Difficulties in acquiring new memories
define: retrograde amnesia
difficulties remembering events from before their brain injury
what were HM’s symptoms?
Minor retrograde amnesia (for events within the 2 years preceding the surgery)
Profound anterograde amnesia: could not form long-term memories for events after surgery
- limited to declarative/explicit memory
- Global amnesia: affecting all sensory
modalities
what is the medial temporal lobe’s role in memory?
critical for making new memories and retrieving old
what is the subsequent memory paradigm used for?
evaluate encoding-phase activity leading to successful versus unsuccessful memory
what part of the PFC is predictive of later remembered/forgotten stimuli?
left ventrolateral PFC
what is the perirhinal cortex’s role in declarative memory?
processes item representations (important for
familiarity)
what is the parahippocampal cortex’s role in declarative memory?
process “context” (including scene perception)
what is the hippocamus’ role in declarative memory?
binds items in context (important for recollection).
which part of the medial temporal lobe predicts familiarity-based recognition?
perirhinal cortex
which part of the medial temporal lobe predicts recollection-based recognition?
hippocampus
define: consolidation
process that stabilises a memory over time after it is first acquired
what is involved with synaptic consolidation?
§ Structural changes in the synaptic connections between neurons
§ May take hours – days to complete
what is involved in system consolidation?
Gradual shift of memory from hippocampus to the cortex
what are the two theories of system consolidation (related to hippocampal function)
Standard consolidation theory: Temporary role of hippocampus
Multiple trace theory: Permanent role of the hippocampus
what is ribot’s law?
Memory loss following brain damage has a
temporal gradient
More recent memories are more likely to be
lost than remote memories
what is the explanation for ribot’s law?
remote memories have undergone systems consolidation – they do not rely upon the MTL anymore, but are cortex -dependent
what characterises Korsakoff’s syndrome?
problems learning new information, inability to remember recent events and long-term memory gaps - temporal gradient in amnesia
explain the standard consolidation model of declarative memory
- The hippocampus links together different kinds of information in many regions of brain (perceptual, affective, conceptual etc.)
- Hypothesis: Initially, hippocampus plays an active role in ‘binding’ the activity of disparate cortical ‘modules’
- Over time, the hippocampus plays less of a role
how does a memory change from hippocampus to cortex dependent?
memory reactivation - iteratively leads to stabilisation & refinement
when a memory has been consolidated, where does the memory cue retrieve the memory from?
cortical network
where in the brain is semantic dementia linked to atrophy?
temporal lobes (cortex)
what characterises semantic dementia?
can remember recent but not old events because memories not yet completely dependent on cortex – yet to be transferred out of hippocampus
where in the brain is related to Alzheimer’s?
hippocampus & related structures
what is the multiple trace theory of system consolidation (related to hippocampal function)
- The hippocampus never ceases to have an important role in episodic memory recall
- Older memories have been reactivated many times over the years
- Each reactivation creates new traces in the MTL and in other neocortical structures
- To the extent that damage is not global, older
- memories are more likely to be remembered as they have multiple traces
- Older memories become more semantic-like
e.g., stories without episodic detail
how does retrograde amnesia evidence the standard consolidation theory of memory consolidation?
the temporal gradient of amnesia reflect the temporal gradient of transfer of memory to the cortex
what is the fMRI evidence of hippocampus activity related to episodic memory?
- Hippocampus activated for both recent and remote memories
- Hippocampal activation was related to the richness of re-experiencing (vividness) rather than the age of the memory per se
- backs up multiple trace theory
what is the difference between recollection-based recognition & familiarity-based recognition?
recollection-based recognition = hippocampus for everything
familiarity-based recognition = specialisation across the MTL (eg faces in amygdala and scenes somewhere else)
