Amnesia Loss of memory ability - usually due to lesion or surgical removal of various parts of the brain

Causes of Amnesia Concussion Migraines Hypoglycemia Epilepsy Electroconvulsive shock therapy Specific brain lesions (i.e. surgical removal) Ischemic events Drugs (esp. anesthetics) Infection Psychological Nutritional deficiency Lack of Sleep!

Amnesia Loss of memory ability - usually due to lesion or surgical removal of various parts of the brain Two broad categories: –Retrograde: loss of memories for events prior to damage

Amnesia Loss of memory ability - usually due to lesion or surgical removal of various parts of the brain Two broad categories: –Retrograde: loss of memories for events prior to damage –Anterograde: loss of ability to store new memories of events after damage

Retrograde Amnesia Anterograde Amnesia

Short-term and sensory memory are typically functional

Korsakoff’s Syndrome The Lost Mariner - What happened to Jimmie? What was his life like?

Korsakoff’s Syndrome (The Lost Mariner) Lesions to Medial Thalamus –Results from chronic alcoholism and consequent thiamine deficiency

Korsakoff’s Syndrome (The Lost Mariner) Lesions to Medial Thalamus –Results from chronic alcoholism and consequent thiamine deficiency –Severe anterograde amnesia

Korsakoff’s Syndrome (The Lost Mariner) Lesions to Medial Thalamus –Results from chronic alcoholism and consequent thiamine deficiency –Severe anterograde amnesia –Severe retrograde amnesia extending years before damage

Korsakoff’s Syndrome (The Lost Mariner) Lesions to Medial Thalamus –Results from chronic alcoholism and consequent thiamine deficiency –Severe anterograde amnesia –Severe retrograde amnesia extending years before damage –Confabulation - make up stories to explain absence of memory

Korsakoff’s Syndrome (The Lost Mariner) Lesions to Medial Thalamus –Results from chronic alcoholism and consequent thiamine deficiency –Severe anterograde amnesia –Severe retrograde amnesia extending years before damage –Confabulation - make up stories to explain absence of memory –Often unaware of their deficit

H. M. Patient H. M. - suffered from extreme epilepsy

H. M. Patient H. M. - bilateral resection of medial temporal lobes (containing hippocampus) –William Beecher Scoville and Brenda Milner - late 1950’s

H. M. Patient H. M. - bilateral resection of medial temporal lobes (containing hippocampus) –William Beecher Scoville and Brenda Milner - late 1950’s –Severe anterograde amnesia

H. M. Patient H. M. - bilateral resection of medial temporal lobes (containing hippocampus) –William Beecher Scoville and Brenda Milner - late 1950’s –Severe anterograde amnesia –Retrograde amnesia for years before surgery

H. M.

Some aspects of memory were spared (at least to some extent)

H. M. Some aspects of memory were spared (at least to some extent) –Procedural memory was largely unaffected - amnesia was largely restricted to episodic memory

H. M. Some aspects of memory were spared (at least to some extent) –Procedural memory was largely unaffected - amnesia was largely restricted to episodic memory –Some implicit awareness of recent events

H. M. Some aspects of memory were spared (at least to some extent) –Procedural memory was largely unaffected - amnesia was largely restricted to episodic memory –Some implicit awareness of recent events –Normal digit span (short-term memory) !

Hypermnesia - S. “Photographic” extreme memory ability (a mnemonist)

Hypermnesia - S. “Photographic” extreme memory ability (a mnemonist) Able to recall complex test stimuli

Hypermnesia - S. S. used two “strategies” or abilities typical of mnemonists: –Rich synesthesia-like quality to his perception of stimuli - leads to stronger associative links

Hypermnesia - S. S. used two “strategies” or abilities typical of mnemonists: –Rich synesthesia-like quality to his perception of stimuli - leads to stronger associative links –Vivid and elaborate mental imagery of things he should remember

Hypermnesia - S. “ Even numbers remind me of images. Take the number 1. This is a proud, well-built man; 2 is a high-spirited woman; 3 a gloomy person (shy, I don’t Know); 6 a man with a swollen foot...” Luria, A.R. The mind of a mnemonist Luria, A.R. The man with a shattered world. 1972

Next Time Awareness and Your Brain