Disorders of High Level Functions Amnesia Aphasia and

Disorders of High Level Functions: Amnesia, Aphasia, and Prosopagnosia Arielle Tambini SPLASH November 21, 2004 MIT Braintrust

Memory n n Explicit/semantic Implicit/episodic Long-term Short-term

Amnesia n n Causes Retrograde Anterograde Transient global

HM n n Epilepsy treatment Anterograde amnesia n n n Long-term explicit memory deficits Short-term intact “You just remember 8. You see 5, 8, 4 add to 17. You remember 8; subtract from 17 and it leaves 9. Divide 9 by half and you get 5 and 4, and there you are – 584. ”

Temporal-lobe Amnesia n Intact implicit memories n n Blinking study Motor tasks Computer programming Role of hippocampus n Imaging studies

Episodic memory deficits n Developmental n n n Loss of blood flow Bilateral hippocampal damage Prefrontal damage “Childhood amnesia” Aging Korsakoff’s syndrome

Aphasia n n Definition Left hemisphere Causes History

Broca’s/nonfluent aphasia n Characteristics n n Anomia Short sentences Language comprehension Broca’s area n Theories of function

Broca’s/nonfluent aphasia “I asked Mr. Ford about his work before he entered the hospital. ‘I’m a sig… no… man… uh, well, … again. ” These words were emitted slowly, and with great effort. The sounds were not clearly articulated; each syllable was uttered harshly, explosively, in a throaty voice. With practice, it was possible to understand him, but at first I encountered considerable difficulty with this. ‘Let me help you, ’ I interjected. ‘You were a signal…” ‘A signal man… right, ’ ‘Were you in the Coast Guard? ’ ‘No, er, yes. . . Ship… Massachu… chusetts… Coastguard… years. ’ He raised his hands twice, indicating the number 19.

Wernicke’s/fluent aphasia n Characteristics n n Comprehension and production loss Speech n n “Nothing the keesereez the, these are davereez and these and this one and these are living. This one’s right in and these are … uh… and that’s nothing, that’s nothing. ” Wernicke’s area n Normal function

Aphasias n Broca’s vs. Wernicke’s n n Apraxia (action) Agnosia (perception) Other areas Severity n Onset

Aphasias n Handedness n n n Language localization Recovery Bilingual aphasics Deafness and aphasia? Plasticity

Agnosia n Definition n Prosopagnosia n n n Causes Intact object recognition Recognition of face

Prosopagnosia n Face perception n n Fusiform Face Area (FFA) Holistic processing Expertise Greeble training