L10 Episodic memory

Question 1

what is episodic memory

Answer 1

combo of what-where-when

Question 2

Nicky Clayton’s Scrub Jays

Answer 2

• stole food to eat later
• remember what was stored and where
• could also retrieve food that was still ok to eat, perished items not retrieved
• scrub jays chose to store food in an empty compartment - consistent with planning for their future hunger

Question 3

which areas of brain responsible for WWW

Answer 3

where - hippocampus
what - perirhinal cortex
which - postrhinal cortex

Question 4

3xTgAD model

Answer 4

• mouse expressed human familial AD transgenes for amyloids
• develops Aß and pTau pathology
• spatial memory and synaptic plasticity deficits from 4 months
• they could still recognise novel objects

Question 5

what-where task in AD mice

Answer 5

• not very good

Question 6

what-which task

Answer 6

• fine with
• memory for object and context is dependent on postrhinal cortex

Question 7

what-where-when task

Answer 7

• can solve task by familiarity

Question 8

3 models of hippocampus role in long-term remote memory retrieval

Answer 8

Standard consolidation theory (SCT), Multiple trace/trans transformation theory (MTT), Scene construction theory

Question 9

SCT

Answer 9

standard consolidation theory:
- Hippocampus not required for remote memory recall - all remote memories spared after hippocampal damage

Question 10

MTT

Answer 10

multiple trace:
- hippocampus IS required for detailed remote memory recall
- cumulative storage in hippocampus with repeated retrieval, adding aspects of attended info at point of retrieval
- with age, apisodic memories become semantic
- need hippocampus for full richness of memory

Question 11

Scene Construction Theory

Answer 11

• hippocampus reconstructs remote episodic memory from neocortically-consolidated elements
• hybrid of SCT and MTT
• no remote storage in hippocampus
• hippocampus needed to reconstruct elements from neocortical elements
• can’t explain richness requirement

Question 12

central issues in debate on LTM episodic recall?

Answer 12

1. over time, episodic memories can become semantic in nature - so after conversion, recall is independent of hippocampus?
2. quality of recall for remote episodic memories after hippocampal damage could be deficient. MTL amnesics may show basic remote episodic memory, so may appear to have no remote memory deficit. but for complete detailed recall you may need hippocampus

so… recall success in MTL amnesics may depend on how you test subject (for ‘richness’)

Question 13

what is the general agreement for hippocampus role in episodic memory

Answer 13

1. Hippocampus is required for episodic memory acquisition (STM–>LTM)
2. Hippocampus is NOT required for STM recall
3. hippocampus is NOT required for storage or recall or semantic memory