Download Amnesia and Alzheimer

Amnesia and Alzheimer’s
Place photo here
Kim Hyun-woo.
Questions
• What are Amnesia , Alzheimer’s and Dementia?
• Where is Memory?
• What hypothesis can you make from these
disease? And Design your own experiments to
prove or disprove it.
Contents
• What is Amnesia?
• Classifying Amnesia.
• H.M. : A Case Study
• 3 experimental ways (free recall, recognition, cuedrecall )
• What is Alzheimer?
• Memory Span
• Working Memory
• Autobiographical Memory
• Semantic Memory
• Implicit Memory
• Location of Memory and the role of hippocampus.
Amnesia ( From Wikipedia )
• Condition in which memory is disturbed
• the inability to imagine the future.
• amnesiacs with damaged hippocampus cannot
imagine the future.
(Reference) Patients with hippocampal amnesia
cannot imagine new experiences
Dementia ( From Wikipedia )
• Etymology
from Latin de- "apart, away" + mens (genitive mentis) "mind")
•
the progressive decline in cognitive function due to
damage or disease in the body beyond what might be
expected from normal aging.
• reversible or irreversible, depending upon the etiology of
the disease.
• Alzheimer's disease (AD) is the most common form of
dementia.
• This is incurable, degenerative, and terminal disease.
• Irreversible , not known etiology.
Amnesia ( Category )
• Retrograde (partial or complete) / Anterograde
• Cause
• Location of the brain damage
particular parts in the brain are implicated in
memory and amnesia
• Functional deficit
H.M. : A case study
• 27 years old
• For alleviating chronic epileptic seizers
surgeons severed his hippocampus
• Alleviation of seizers
• But, severe disruption of memory
• Normal on immediate tests , otherwise no
memory on delayed test.
Theoretical Accounts of Amnesia(1)
• Hippocampus is involved in mediating memory.
Cons. - maybe surgeons damaged other parts
• Short term memory / Long term memory
Cons.- short memory span doesn’t mean an impaired long term
memory.
• More recent claim, procedural / declarative memory
According to Cohen & Eichenbaum, amnesiacs can learn the
solution of the Tower of Hanoi problem. (still controversial)
Amnesiacs
Control subjects
First Day
48.6
46.7
Forth Day
34.1
33.5
Optimal Performance
31
Theoretical Accounts of Amnesia(2)
• Implicit and explicit Memory (chapter 7)
• Retrieval Problem
Test
Recall
Recognition
Fragmented Word
( Cued-Recall )
Control subjects Amnesic Subjects
48 %
14 %
94 %
59 %
96 %
94 %
Theoretical Accounts of Amnesia(3)
• The role of context
Theoretical Accounts of Amnesia(4)
• Amnesiacs can use familiarity on many tasks, this use is
impaired relative to controls.
• Control subjects can use familiarity and conscious
recollection.
Alzheimer’s Disease(AD)
• Reported the first case in 1907
• Alzheimer’s Disease is still poorly understood.
• Amyloid plaques , neurofibrillary tangles are
abnormal structure in the brain of AD patients
• Beta amyloid is toxic to neurons
Alzheimer’s Disease(AD)
Difficulties to understand
-
No symptom
-
Significant cognitive decline with no obvious
cause
-
As the disease progresses, more areas are
affected
-
MRI,CT
-
PET, fMRI are sometime useful
are useless
Amnesia vs Alzheimer’s
Amnesia
Alzheimer’s
delayed free recall
X
X
recognition
X
X
procedural learning
O
X
priming
O
X
X : impaired
O : intact
Alzheimer’s
• In the early stages of disease, even though
decreased memory performance,
the bow shape of serial curve
• Short memory span
• Small working memory ( Figure 8.8 )
Alzheimer’s
( Autobiographical memory )
Bow-shaped serial position curve
Alzheimer’s
( Semantic memory )
• Alzheimer’s patients tend to represent objects in
term of concrete dimensions such as size instead
of abstract dimensions
Where is memory?
• Localized vs Distributed
• H.M. Case : hippocampus serves the important
role of memory.
•
During intentional memory encoding and
retrieval, universal activation.
• On evolutionary grounds, Reliance on a central
memory organ would also be problematic.
Questions
• What are Amnesia , Alzheimer and Dementia?
- Skip
• Where is Memory?
- I agree with the point of view that memory is
distributed.
• What hypothesis can you make from these
disease? And Design your own experiments to
prove or disprove it.
-
Procedural memory is longer than Declarative
memory.
Q&A