Lecture 17 - Amensia and The Brain Flashcards

1
Q

Outline Retrograde Amnesia

A

Cannot remember events prior to brain damage

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2
Q

Outline Anterograde Amnesia

A

Cannot later remember events occur after brain damage

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3
Q

Causes of Anterograde Amnesia

A
Alzheimer’s 
Korsakoffs 
Herpes encephalitis 
Anoxia/Ischaemja 
Injuries or rumours limbus system 
Surgeries for epilepsy 
Degenerative brain diseases
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4
Q

Outline Korsakoffs Pscyhosis

A

Reflecting gradual onset
Confabulation
Associated thymine deficiency - vitamin B
Make up stories

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5
Q

Outline Anoxia/Ischaemia

A

Result very selective AA
Aschemic brain damage
Interruption oxygen supply

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6
Q

Outline degenerative brain diseases

A

Schiz
Advanced multiple sclerosis
Huntington’s disease

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7
Q

Outline hippocampus particularly sensitive anoxia

A

Damage field CA1 caused anoxia
Effect oxygen deprivation hippocampus
Both rats and humans distinctive cell layering hippocampus
Structure less well defined and organised

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8
Q

Outline Neural substrates of Hippocampus and associated structures

A

Cortical connections hippocampal formation
Hippocampus lies beneath not truly sub-cortical, rather primitive-cortical infolding mamilliary bodies also implicated amnesia
Lessons similar profile memory loss

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9
Q

Outline HM case study by Milner et al 1968

A
Epileptic seizures 
Bilateral media temporal lobe removed 
Anterograde amnesia 
Above average IQ, normal perceptual, good memory events prior 
Selective
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10
Q

Outline pure amnestied syndrome

A

HM - Milner
Poor LTM for new material
Perceptual/motor learning intact
Claperede Effect

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11
Q

Outline the Clapered Effect

A

Patient amnesia testing his reflexes
Pin method - patient poked pin
Went to do re-test following session
Patient didn’t remember pin but did say researcher may have pin in his hand

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12
Q

Outline the nature of the deficit

A
  1. Selective effect LTM
  2. Global - impairments across modalities and materials
  3. Selective - impairments remembering new facts and events
  4. Selective - spares learning and expression skilled performance
  5. Info inflexible and expressed limited contexts
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13
Q

Outline effective effect on the LTM

A

Digit span normal 7 +- 3
Extended: multiple repetitions up to 20
HM not recall string excess normal STM even after 25 repetitions

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14
Q

Outline global impairments across different modalities and materials

A

Tests: free, cued recall, recognition
Modalities: amnesia seen information presented different modalities
Visual, auditory, olfactory - different visual agnosia

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15
Q

Outline selective impairments remembering new facts and events

A

HM unable report any personal or public events since surgery
Impaired list based tasks - paired associate learning
Task recall given first word cue
Compare learning face name pairings, new word meanings

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16
Q

Outline evidence impaired memory for new facts and events in HM

A

Take word rather obscure and measure capacity learning and remembering word 3 ways: definition, synonyms, sentences
HM amnesia affects stable, no recovery across 3 years two time points
High test retest reliability

17
Q

Outline amnesia spares learning and expression skilled performance for repetition priming

A

Repetition priming - show something visually lager influence you. Even if don’t remember.

Picture fragment completion and word stem completion

18
Q

Outline amnesia spares learning and expression skilled performance for mirror tracing

A
Reproducing outline 
Star with only visual info from mirror 
Amnesiacs show savings 
Learning draw what you can’t see only from feedback from mirror 
Normal people get better over time
19
Q

Outline amnesia spares learning and expression skilled performance for mirror image reading task

A

Given word triplets read
Amnesiacs get fast and accurate with multiple presentations
Normal people enter over time
Despite: little no memory learning experience
Little recall/recognition test
Little no insight skills acquired

20
Q

Outline evidence for spares skilled performance broken, degraded drawings

A

Earlier exposed completed image even if don’t remember be much better picture completion
Neurologically intact recognise at an even more incomplete stage

21
Q

Snodgrass and Feenan 1990 picture fragmentation completion

A
Ppts required join up dots 
Which you produce influenced what saw earlier 
Also in amnesiac patients 
Procedural learning and memory in tact 
Repetition priming
22
Q

Cohen and Squire 1980 mirror image word sets

A

Mirror image reading task only feedback mirror
Improved reading times over trials
For new non repeated sets words
Perceptual skill learned even those in amnesia

23
Q

Outline inflexibility and having little transfer

A

Performance measures exactly same way show savings

Facilitation does not carry over other tasks or contexts

24
Q

Outline amnesiacs dissociation between cues recall and word stem completion

A

Impaired cued recall
But biased previous word exposures asked complete word stems ‘1st word comes mind’ first few letters = cues
Amnesiacs so bad often recalling from previous learnt think - interference

25
Outline Amnesiacs being bad at knowing when paired associate task by Winocur and Weiskrantz 1976
Averaging strategy Amnesiacs bad unrelated pairs Ok words combined according semantic of phonetic properties Retention 30 mins ok but couldn’t learn second paired associate list be because high number list 1 intrusions
26
Theoretical accounts
Procedural vs Declarative memory - Squire 1992 Semantic vs episodic - Tulving 1972
27
Outline if there are two or more memory systems
Declarative/episodic vs Procedural/semantic Wider circuit not just hippocampus Pure amnesia damage mammillary bodies
28
Outline if there are two or more memory systems differences Amnesiacs and Korsakoffs
Korsakoffs differ from temporal lobe amnesiacs Maybe just additional deficits associated brain damage - frontal lobe signs Other degenerative conditions show additional deficits - demand confusion, Schiz