Amnesia and Role of MTL Flashcards
amnesia
loss of memory function
anterograde amnesia
inability to remember new events
retrograde amnesia
inability to remember old memories (often temporally graded, so can’t remember memories from right before injury
-HM, EP
MTL damage
- GLOBAL impairments
- impaired all types of tests, materials and modalities
Medial temporal lobe
- hippocampus
- amygdala
- parahippocampal cortex
- entorhinal cortex
- perirhinal cortex
Hierarchy of information flow
- primary sensory areas (not MTL)
-association areas (not MTL)
-perirhinal and parahippocampas cortex
-entorhinal cortex
hippocampus
Role of hippocampus in information flow
- information converges at hippocampus
- hippocampal neurons can easily form connections
- damage to hippocampus can cause amnesia
- more MTL damage leads to more amnesic syndrome
Alzheimer’s
-damage in entorhinal cortex
Relational Memory theory
- MTL forms the binds between features
- hippocampus (and parahippocampal region) supports declarative memory
- hippocampus rapidly acquires representation associations
- representations flexibly addressable
- MTL cortex contributes to memory for individual items/features.
- hippocampal neurons bind in response to sensory info
- need representation in hippocampus to be build to remember events
declarative memory is _______
relational
What does the perirhinal cortex encode
items
what
what does the parahippocampal cortex encode
context
where
what is the role of the entorhinal cortex is encoding?
separates what from where
role of hippocampus in encoding?
binds items and context
Dissociable MTL encoding effects: item-context associations vs item recognition
-Davachi, Mitchell, Wagner (2003)
Study:
-context 1: visual memory
-context 2: phonological memory
Test:
-have them remember the words and context (whether it was visual or phonological)
-perirhinal activity predicts item learning
- hippocampus activity predicts item + context memory (but not item only)
