AmnesiaAmnesiaWhat is it?What is it?

Memory Memory

Proposed Types of Proposed Types of MemoryMemory

Fact memoryFact memory Skill memorySkill memory

DeclarativeDeclarative Non-declarative Non-declarative (Procedural)(Procedural)

MemoryMemory HabitHabit

ExplicitExplicit ImplicitImplicit

Knowing thatKnowing that Knowing HowKnowing How

Cognitive mediationCognitive mediation SemanticSemantic

Conscious recollectionConscious recollection SkillsSkills

ElaborationElaboration IntegrationIntegration

Autobiographical Autobiographical PerceptualPerceptual

RepresentationalRepresentational DispositionalDispositional

Vertical associationVertical association Horizontal associationHorizontal association

EpisodicEpisodic SemanticSemantic

AmnesiaAmnesia

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

AmnesiaAmnesia

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

Two broad categories:Two broad categories: RetrogradeRetrograde: loss of memories for : loss of memories for

events prior to damageevents prior to damage

AmnesiaAmnesia

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

Two broad categories:Two broad categories: RetrogradeRetrograde: loss of memories for : loss of memories for

events prior to damageevents prior to damage AnterogradeAnterograde: loss of ability to store : loss of ability to store

new memories of events after damagenew memories of events after damage

AmnesiaAmnesia

Short-term and sensory memory are Short-term and sensory memory are typically functionaltypically functional

AmnesiaAmnesia

Amnesia patients exhibit recency Amnesia patients exhibit recency effect but not primacy effecteffect but not primacy effect

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Causes of AmnesiaCauses of Amnesia

ConcussionConcussion MigrainesMigraines HypoglycemiaHypoglycemia EpilepsyEpilepsy Electroconvulsive shock therapyElectroconvulsive shock therapy Specific brain lesions (i.e. surgical removal)Specific brain lesions (i.e. surgical removal) Ischemic eventsIschemic events Drugs (esp. anesthetics)Drugs (esp. anesthetics) InfectionInfection PsychologicalPsychological Nutritional deficiencyNutritional deficiency

Amnesia - associated Amnesia - associated brain regionsbrain regions

Diencephalic amnesia - damage to Diencephalic amnesia - damage to the the medial thalamusmedial thalamus and and mammillary mammillary nucleinuclei

Amnesia - associated Amnesia - associated brain regionsbrain regions

Diencephalic amnesia - damage to Diencephalic amnesia - damage to the medial thalamus and mammillary the medial thalamus and mammillary nucleinuclei

Medial temporal lobe amnesia - Medial temporal lobe amnesia - damage to the damage to the hippocampal hippocampal formation, uncus, amygdalaformation, uncus, amygdala, and , and surrounding cortical areassurrounding cortical areas

Amnesia - associated Amnesia - associated brain regionsbrain regions

Diencephalic amnesia - damage to the Diencephalic amnesia - damage to the medial thalamus and mammillary nucleimedial thalamus and mammillary nuclei

Medial temporal lobe amnesia - damage Medial temporal lobe amnesia - damage to the hippocampal formation, uncus, to the hippocampal formation, uncus, amygdala, and surrounding cortical amygdala, and surrounding cortical areasareas

Other implicated regions include Other implicated regions include Anterior Lateral Temporal LobeAnterior Lateral Temporal Lobe and and Frontal LobesFrontal Lobes

AmnesiaAmnesia

Hippocampus Thalamus

Diencephalic AmnesiaDiencephalic Amnesia

Damage to the Damage to the medial thalamus medial thalamus and/or mammillary and/or mammillary bodiesbodies strokestroke

Korsakoff’s Korsakoff’s syndromesyndrome Caused by thiamine Caused by thiamine

deficiency as a deficiency as a result of chronic result of chronic alcoholismalcoholism

Korsakoff’s SyndromeKorsakoff’s Syndrome

The Lost MarinerThe Lost Mariner - What happened to - What happened to Jimmie? What was his life like?Jimmie? What was his life like?

Korsakoff’s Syndrome Korsakoff’s Syndrome (The Lost Mariner)(The Lost Mariner)

Lesions to Medial ThalamusLesions to Medial Thalamus Results from chronic alcoholism and Results from chronic alcoholism and

consequent thiamine deficiencyconsequent thiamine deficiency

Korsakoff’s Syndrome Korsakoff’s Syndrome (The Lost Mariner)(The Lost Mariner)

Lesions to Medial ThalamusLesions to Medial Thalamus Results from chronic alcoholism and Results from chronic alcoholism and

consequent thiamine deficiencyconsequent thiamine deficiency Severe anterograde amnesiaSevere anterograde amnesia

Korsakoff’s Syndrome Korsakoff’s Syndrome (The Lost Mariner)(The Lost Mariner)

Lesions to Medial ThalamusLesions to Medial Thalamus Results from chronic alcoholism and Results from chronic alcoholism and

consequent thiamine deficiencyconsequent thiamine deficiency Severe anterograde amnesiaSevere anterograde amnesia Severe retrograde amnesia extending Severe retrograde amnesia extending

years before damageyears before damage

Korsakoff’s Syndrome Korsakoff’s Syndrome (The Lost Mariner)(The Lost Mariner)

Lesions to Medial ThalamusLesions to Medial Thalamus Results from chronic alcoholism and Results from chronic alcoholism and

consequent thiamine deficiencyconsequent thiamine deficiency Severe anterograde amnesiaSevere anterograde amnesia Severe retrograde amnesia extending Severe retrograde amnesia extending

years before damageyears before damage Confabulation - make up stories to Confabulation - make up stories to

explain absence of memoryexplain absence of memory

Korsakoff’s Syndrome Korsakoff’s Syndrome (The Lost Mariner)(The Lost Mariner)

Lesions to Medial ThalamusLesions to Medial Thalamus Results from chronic alcoholism and Results from chronic alcoholism and

consequent thiamine deficiencyconsequent thiamine deficiency Severe anterograde amnesiaSevere anterograde amnesia Severe retrograde amnesia extending Severe retrograde amnesia extending

years before damageyears before damage Confabulation - make up stories to Confabulation - make up stories to

explain absence of memoryexplain absence of memory Often unaware of their deficitOften unaware of their deficit

Medial Temporal lobe Medial Temporal lobe amnesiaamnesia

Hippocampus is most important site Hippocampus is most important site of damageof damage

H. M.H. M.

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

H. M.H. M.

Patient H. M. - bilateral resection of Patient H. M. - bilateral resection of medial temporal lobes (containing medial temporal lobes (containing hippocampus)hippocampus) William Beecher Scoville and Brenda William Beecher Scoville and Brenda

Milner - late 1950’s Milner - late 1950’s

H. M.H. M.

Patient H. M. - bilateral resection of Patient H. M. - bilateral resection of medial temporal lobes (containing medial temporal lobes (containing hippocampus)hippocampus) William Beecher Scoville and Brenda William Beecher Scoville and Brenda

Milner - late 1950’sMilner - late 1950’s Severe anterograde amnesiaSevere anterograde amnesia

H. M.H. M.

Patient H. M. - bilateral resection of Patient H. M. - bilateral resection of medial temporal lobes (containing medial temporal lobes (containing hippocampus)hippocampus) William Beecher Scoville and Brenda William Beecher Scoville and Brenda

Milner - late 1950’s Milner - late 1950’s Severe anterograde amnesiaSevere anterograde amnesia Retrograde amnesia for 1 - 3 years Retrograde amnesia for 1 - 3 years

before surgery before surgery

H. M.H. M.

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H. M.H. M. Patient H. M. - bilateral resection of Patient H. M. - bilateral resection of

medial temporal lobes (containing medial temporal lobes (containing hippocampus)hippocampus) William Beecher Scoville and Brenda William Beecher Scoville and Brenda

Milner - late 1950’s Milner - late 1950’s Severe anterograde amnesiaSevere anterograde amnesia Retrograde amnesia for 1 - 3 years Retrograde amnesia for 1 - 3 years

before surgery before surgery Disconnection of autonomic responses Disconnection of autonomic responses

such as hunger/satiety and Galvanic such as hunger/satiety and Galvanic Skin Response (GSR)Skin Response (GSR)

H. M.H. M.

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

H. M.H. M.

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

unaffected - amnesia was largely unaffected - amnesia was largely restricted to episodic memoryrestricted to episodic memory

H. M.H. M.

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

unaffected - amnesia was largely unaffected - amnesia was largely restricted to episodic memoryrestricted to episodic memory

Some implicit awareness of recent Some implicit awareness of recent eventsevents

H. M.H. M.

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

unaffected - amnesia was largely unaffected - amnesia was largely restricted to episodic memoryrestricted to episodic memory

Some implicit awareness of recent Some implicit awareness of recent eventsevents

Normal digit span (short-term Normal digit span (short-term memory) !memory) !

E. P.E. P.

Suffered acute viral disease in brainSuffered acute viral disease in brain Damage sustained in temporal lobes, Damage sustained in temporal lobes,

notably the hippocampusnotably the hippocampus

E. P.E. P.

Suffered acute viral disease in brainSuffered acute viral disease in brain Damage sustained in temporal lobes, Damage sustained in temporal lobes,

notably the hippocampusnotably the hippocampus Displays anterograde amnesiaDisplays anterograde amnesia

Short term memory intactShort term memory intact Lives in a permanent presentLives in a permanent present

E. P.E. P.

Suffered acute viral disease in brainSuffered acute viral disease in brain Damage sustained in temporal lobes, Damage sustained in temporal lobes,

notably the hippocampusnotably the hippocampus Displays anterograde amnesiaDisplays anterograde amnesia

Short term memory intactShort term memory intact Lives in a permanent presentLives in a permanent present

What else can we infer from the What else can we infer from the interview seen?interview seen?

Hypermnesia - S.Hypermnesia - S.

““Photographic” extreme memory Photographic” extreme memory ability (a mnemonist)ability (a mnemonist)

Hypermnesia - S.Hypermnesia - S.

““Photographic” extreme memory Photographic” extreme memory ability (a mnemonist)ability (a mnemonist)

Able to recall complex test stimuli Able to recall complex test stimuli

Hypermnesia - S.Hypermnesia - S.

S. used two “strategies” or abilities S. used two “strategies” or abilities typical of mnemonists:typical of mnemonists: Rich synesthesia-like quality to his Rich synesthesia-like quality to his

perception of stimuli - leads to stronger perception of stimuli - leads to stronger associative linksassociative links

Hypermnesia - S.Hypermnesia - S.

S. used two “strategies” or abilities S. used two “strategies” or abilities typical of mnemonists:typical of mnemonists: Rich synesthesia-like quality to his Rich synesthesia-like quality to his

perception of stimuli - leads to stronger perception of stimuli - leads to stronger associative linksassociative links

Vivid and elaborate mental imagery of Vivid and elaborate mental imagery of things he should rememberthings he should remember

Hypermnesia - S.Hypermnesia - S.

“ “ Even numbers remind me of Even numbers remind me of images. Take the number 1. This is images. Take the number 1. This is a proud, well-built man; 2 is a high-a proud, well-built man; 2 is a high-spirited woman; 3 a gloomy person spirited woman; 3 a gloomy person (shy, I don’t Know); 6 a man with a (shy, I don’t Know); 6 a man with a swollen foot...”swollen foot...”

Luria, A.R. The mind of a mnemonist. 1968

Luria, A.R. The man with a shattered world. 1972

AmnesiaAmnesia

What pattern of result can be seen across these patient’s cases? What does it suggest about memory systems?

Dissociation of Memory Dissociation of Memory SystemsSystems

Memory systems are “doubly-Memory systems are “doubly-dissociated”dissociated”

Dissociation of Memory Dissociation of Memory SystemsSystems

Memory systems are “doubly-Memory systems are “doubly-dissociated”dissociated” Patient H.M.’s lesion affected only Patient H.M.’s lesion affected only

episodic long-term memory - semantic episodic long-term memory - semantic and procedural memory were intact - and procedural memory were intact - short-term memory was intactshort-term memory was intact

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