Transcript Anterograde Amnesia

Anterograde Amnesia
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Retrograde Amnesia
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Impairment of memory for events
before the injury.
Anterograde Amnesia
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Impairment of memory for events after
an injury.
 That is, an impairment in learning.
Types by Duration
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Temporary
Drug induced
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Lithium
Alcohol
tricyclic
antidepressants
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e.g., valium (Judd et al.
1987)
Shock/Trauma
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e.g., ECT used for
depression
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Chronic
Alcohol
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Trauma –
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- reversible with
abstinence (over years)
e.g., injury, disease,
toxins, anoxia
Progressive
Alzheimer’s
Huntington’s
Normal Aging
Medial Temporal Amnesia 1
Bilateral damage to
medial temporal
region including
hippocampus
Medial Temporal Amnesia 2
Most famous cases are:
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H. M. (surgery)
S. S. (encephalitus)
R.B. (blood supply to area cut off by atrial
tear)
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(Zola-Morgan, Squire, & Amaral, 1986).
Medial Temporal Amnesia 3
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The semantic (logogen) network
remains intact.
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Normal implicit memory and priming
effects observed (Graf, Shimamura, &
Squire, 1985).
Skill learning unimpaired.
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Patient’s skill improves despite being unable to
recall having done the task before.
Wernicke’s-Korsakoff (KD)
Syndrome 1
Caused by thiamine
deficiency that
results from
alcoholism and
starvation
MRI comparison with
alcoholics shows
damaged
diencephalon
Wernicke’s-Korsakoff
Syndrome 2
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As with Medial Temporal Amnesia,
procedural and implicit memory are
functional.
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Warrington & Weiskrantz (1970; 1974).
Graf, Squire, & Mandler (1984).
Gardner, Boller, Moreines, & Butters
(1973).
Alzheimer’s Disease (AD) 1
Result of plaques
throughout cortex;
early detection now
possible; antiinflammatories (e.
g., aspirin,
ibuprophren) reduce
symptoms
Alzheimer’s Disease 2
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As with other amnesias, procedural
memory remains intact.
However, generalized damage affects
semantic memory, so priming and
implicit memory deficits are seen.
Faster forgetting than others, though.
Verbal fluency problems.
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“Bottom-up” deficits. (Hodges, Salmon, &
Butters, 1992).
Huntington’s Disease (HD)
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Caudate nuclei of basal
ganglia die over time
 Patient loses ability to
make voluntary
responses.
 Inability to make
voluntary response
reduces imagery and
verbal rehearsal
strategies.

Results in poorer recall
than recognition.
Nature of Learning Deficit 1
Task
Example Medial-
Skill
Piano
Learning playing
LanPicture
guage
Naming
Gener- Digit
ation
span
Recog- Faces
nition
Recall
Recent
Events
Temporal
DienBasal
Cephalon Ganglia
KD
HD
normal
normal
impaired normal
normal
normal
normal
normal
normal
impaired impaired
impaired impaired normal
Cortex
AD
impaired
impaired
impaired impaired impaired impaired
Nature of Learning Deficit 2
Task
Example
Motor
Skill
Semantic
Priming
Piano
playing
Wordstem
Verbal
Fluency
Animal
Names
Word
List
Recognition
Recall
Story
DienCephalon
Hippocampal Korsakoff
MedialTemporal
Cortex
Alzheimer’s
Basal
Ganglia
Huntington’s
normal
normal
normal
impaired
normal
normal
impaired
normal
normal
normal
impaired
instances
impaired
impaired
impaired
impaired
normal
impaired
impaired
impaired
impaired
Hippocampus-amygdala lesions in
monkeys
Monkeys no longer remember which
object hides the raisin in a previously
learned discrimination task and
relearning is impaired. However,
retention of an old motor skill, and the
learning of a new motor skill, are
unimpaired (Salmon, Zola-Morgan &
Squire, 1987).