Amnesia and Alzheimer’s

1. Kim Hyun-woo. Place photo here Amnesia and Alzheimer’s

2. 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.

3. Contents • What is Amnesia? • Classifying Amnesia. • H.M. : A Case Study • 3 experimental ways (free recall, recognition, cued-recall ) • What is Alzheimer? • Memory Span • Working Memory • Autobiographical Memory • Semantic Memory • Implicit Memory • Location of Memory and the role of hippocampus.

4. 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

5. 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.

6. 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

7. 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.

8. 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)

9. Theoretical Accounts of Amnesia(2) • Implicit and explicit Memory (chapter 7) • Retrieval Problem

10. Theoretical Accounts of Amnesia(3) • The role of context

11. 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.

12. 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

13. 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 are useless • PET, fMRI are sometime useful

14. Amnesia vs Alzheimer’s

15. 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 )

16. Alzheimer’s ( Autobiographical memory ) Bow-shaped serial position curve

17. Alzheimer’s( Semantic memory ) • Alzheimer’s patients tend to represent objects in term of concrete dimensions such as size instead of abstract dimensions

18. 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.

19. 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.

20. Q & A