Ch 11 Learning, Memory and Amnesia Flashcards
types of amnesia
anterograde (making new memories - generally LTM)
retrograde (forgot before surgery/injury)
what did HM have removed and what was the effect
medial portions of both temporal lobes and hippocampus/part of amygdala
anterograde and retrograde amnesia
working memory intact
what tests show implicit memory
picture completion
mirror drawing
pavlovian conditions
scientific contributions of HM
implicit and explicit LTM
LTM and STM stored differently
medial temporal lobes important in memory
medial temporal lobe amnesia
associated with bilateral damage to these lobes
explicit LTM impaired, implicit is okay
episodic is especially impaired
explicit memory falls into two categories
semantic
episodic
Korsakoff’s syndrome
amnesia associated with heavy alcohol use
thiamine deficiency
Damage: Medial diencephalon (including mediodorsal nuclei of the thalamus), hippocampus, and cerebellum.
Results in anterograde and retrograde amnesia (affecting episodic memory).
Impacts explicit memory more than implicit memory.
Global Cerebral Ischemia
(lack of blood supply to the brain) can cause medial temporal lobe amnesia.
sudden onset often from stroke (4-6 hours of amnesia)
what NT is reduced in alzhiemers patients
acetylcholine
posttraumatic amnesia
symptoms
amnesia following a closed headed TBI
Confusion, coma, retrograde amnesia for the events leading to the injury, and anterograde amnesia for the period afterward.
islands of memory
associated with PTA
Some memories from the confusion period may persist.
loss of recent memories from closed headed TBIs are evidence for
consolidation of memory
current view on consolidation is
continues for a very long time, if not indefinitely
Lasting memories become more and more resistant to disruption throughout life
If a memory is activated it is updated and linked to new memories, strengthening it
consolidation dual-trace theory
Memories are temporarily stored in the hippocampus until they can be transferred to a more stable cortical storage system
when we recall a memory it is held in ___ and is vulnerable and must be ___
labile (STM), reconsolidated
engram
Each time the OG memory is recalled or a similar experience happens, a new engram (change in the brain that stores memory) is established and is linked to the original engram
Morris Water Maze Test:
Rats with hippocampal lesions struggle to learn spatial tasks (finding a hidden platform in water).
This highlights the hippocampus’s role in spatial memory.
Delayed Nonmatching-to-Sample Test:
Monkeys and rats with medial temporal lobe damage have difficulty forming long-term memories for objects in this task.
This supports the idea that hippocampal damage impairs object recognition memory.
Hippocampal Place Cells:
Place cells fire in response to specific locations in an environment.
entorhinal complex
area of medial temporal cortex sending many signals to the hippocampus
Radial Arm Maze Test:
Assesses reference memory (long-term memory for general principles) and working memory (temporary memory for short-term tasks).
Grid cells
neurons in the entorhinal cortex that fire at regular intervals as an animal navigates, contributing to its ability to understand its position in space by creating a “coordinate map
the hippocampus as a cognitive map
place and grid cells = spatial
also temporal aspects and social organization
not just a physical map but a cognitive one
- The major structures of the medial temporal lobes are:
○ Hippocampus
○ Amygdala
○ Medial temporal cortex
