““THE ADVANTAGE OF THE ADVANTAGE OF HAVING BAD MEMORY IS HAVING BAD MEMORY IS

THAT YOU CAN ENJOY GOOD THAT YOU CAN ENJOY GOOD THINGS FOR THE FIRST TIME THINGS FOR THE FIRST TIME

SEVERAL TIMES.”SEVERAL TIMES.”

-FRIEDRICH NIETZSCHE-FRIEDRICH NIETZSCHE

RETROGRADE AND RETROGRADE AND ANTEROGRADE AMNESIAANTEROGRADE AMNESIA

Ellie MoradiEllie MoradiColin SchwartzColin Schwartz

Chris YcoChris YcoMelissa BerghMelissa Bergh

RETROGRADE AMNESIA:RETROGRADE AMNESIA:THE UNDERLYING CAUSE & THE UNDERLYING CAUSE &

PHYSIOLOGYPHYSIOLOGY• Inability to access memories prior to Inability to access memories prior to

damagedamage

• Often associated with Often associated with neurodegenerative diseases such as neurodegenerative diseases such as Alzheimer’s DiseaseAlzheimer’s Disease

• Other causes include trauma, tumors, Other causes include trauma, tumors, cerebrovascular accident (aneurysm), cerebrovascular accident (aneurysm), encephalitis, chronic alcohol use, and encephalitis, chronic alcohol use, and hypoxia (lack of oxygen)hypoxia (lack of oxygen)

HIPPOCAMPUS HIPPOCAMPUS

MEDIAL TEMPORAL LOBEMEDIAL TEMPORAL LOBE

Physiology & Causes Cont’d.Physiology & Causes Cont’d.• Hippocampal damageHippocampal damage

– Hippocampus important for episodic Hippocampus important for episodic and declarative memoryand declarative memory

– Damage makes it difficult to recall Damage makes it difficult to recall memories prior to damagememories prior to damage

– Retrograde amnesia is both extensive Retrograde amnesia is both extensive and ungraded when damage is limited and ungraded when damage is limited to hippocampusto hippocampus

– Damage does not interfere with Damage does not interfere with learning new skills howeverlearning new skills however

Physiology & Causes Cont’d.Physiology & Causes Cont’d.

• Medial Temporal Lobe damageMedial Temporal Lobe damage– The sparing of remote memory after The sparing of remote memory after

damage shows that the importance of damage shows that the importance of the medial temporal lobe structures for the medial temporal lobe structures for memory gradually diminish.memory gradually diminish.

– Often damage is done to the knowledge Often damage is done to the knowledge stores in the MTL affecting the ability to stores in the MTL affecting the ability to recollect memories or information recollect memories or information regardless of when it occurred or was regardless of when it occurred or was learnedlearned

RELATION TO ALTERED STATES RELATION TO ALTERED STATES OF CONSCIOUSNESSOF CONSCIOUSNESS

• Memories and past events are Memories and past events are contributing factors to being an contributing factors to being an individualindividual

• No studies have shown a complete No studies have shown a complete loss of selfloss of self

• The individual adapts to the loss of The individual adapts to the loss of memoriesmemories

Characteristics of RACharacteristics of RA

• Ribot gradientRibot gradient– The tendency to lose The tendency to lose

new memories more new memories more so than old memoriesso than old memories

– Span of loss unique, Span of loss unique, difficult to pinpoint itdifficult to pinpoint it

• Memory lossMemory loss– Retain Retain

autobiographical, autobiographical, semantic, procedural, semantic, procedural, general knowledgegeneral knowledge

– Lose episodic (Brandt Lose episodic (Brandt & Benedict 1993)& Benedict 1993)

–Trevor Rees-Jones (August Trevor Rees-Jones (August 1997)1997)

What can RA tell us about What can RA tell us about memory?memory?

• Memory-Consolidation Theory (McGaugh Memory-Consolidation Theory (McGaugh 1966)1966)– New memory has to be consolidated and if New memory has to be consolidated and if

interrupted leads to RAinterrupted leads to RA– Classical evidence: amnesia inversely related Classical evidence: amnesia inversely related

to the age of the memory (Duncan 1949)to the age of the memory (Duncan 1949)– Problems: RA recovery, delayed-onset RA and Problems: RA recovery, delayed-onset RA and

RA for long-term memory (Krickett Carpenter)RA for long-term memory (Krickett Carpenter)

What can RA tell us about What can RA tell us about memory?memory?

• Multi-trace theory (Nadel et al 2000)Multi-trace theory (Nadel et al 2000)– Hippocampus responsible for encoding Hippocampus responsible for encoding

and retrieving all and retrieving all episodicepisodic memory memory independent of its age and thus damage independent of its age and thus damage randomly causes deficits.randomly causes deficits.

– Old memories well encoded but can Old memories well encoded but can have retrieval problems. have retrieval problems.

– Evidence? Ribot gradients only found in Evidence? Ribot gradients only found in partial lesions of hippocampus in rats.partial lesions of hippocampus in rats.

– No real evidence. If you can figure out a No real evidence. If you can figure out a way to test this, let me know.way to test this, let me know.

What can RA tell us about What can RA tell us about memory?memory?

• Semanticization (Cermak 1984)Semanticization (Cermak 1984)– All memories start out as episodic and All memories start out as episodic and

through over-learning becomes semantic through over-learning becomes semantic which is independent of hippocampus.which is independent of hippocampus.

In concluding RAIn concluding RA

• Should old memory amnesia be Should old memory amnesia be considered with RA?considered with RA?

• No studies to my knowledge No studies to my knowledge comparing brain areas involved in comparing brain areas involved in new and old memory RAnew and old memory RA

• No consensus about RA causeNo consensus about RA cause

RA and ASCRA and ASC

• Sense of self endures in RASense of self endures in RA

• Theoretically if Ribot gradient went Theoretically if Ribot gradient went ad infinitum would forget about self?ad infinitum would forget about self?

• In Semantization, if all memory starts In Semantization, if all memory starts out episodic then awareness out episodic then awareness externally is episodic and semantic externally is episodic and semantic internallyinternally

ANTEROGRADE AMNESIAANTEROGRADE AMNESIA• Anterograde amnesia is a selective Anterograde amnesia is a selective

memory deficit, resulting from brain memory deficit, resulting from brain injury. injury.

CAUSES OF INJURYCAUSES OF INJURY

•StrokeStroke– ischemic stroke, in which a small blood clot becomes ischemic stroke, in which a small blood clot becomes

wedged in one of the tiny blood vessels supplying the wedged in one of the tiny blood vessels supplying the brain, blocking the flow of blood. This blood clot may brain, blocking the flow of blood. This blood clot may have formed in the brain, or it may have formed have formed in the brain, or it may have formed elsewhere, broken free, and traveled through the elsewhere, broken free, and traveled through the blood stream to reach the brainblood stream to reach the brain

•Aneurysm Aneurysm – An aneurysm is a small local bulge in the wall of a An aneurysm is a small local bulge in the wall of a

blood vessel, usually an artery. Normally, blood blood vessel, usually an artery. Normally, blood vessels operate like pipes, carrying blood throughout vessels operate like pipes, carrying blood throughout the body to cells which depend on this supply for the body to cells which depend on this supply for oxygen and nutrients.oxygen and nutrients.

AREAS OF INJURYAREAS OF INJURY

• The first, and most well-studied, is The first, and most well-studied, is the hippocampus.the hippocampus.– Hippocampus is seen as the gateway Hippocampus is seen as the gateway

through which new information must through which new information must pass before being stored into long term pass before being stored into long term memory. memory.

– Once this is damaged, it is almost Once this is damaged, it is almost impossible to create new memories. impossible to create new memories.

INJURY CONT’D.INJURY CONT’D.

• Long-Term Potentiation (LTP)Long-Term Potentiation (LTP)– This occurs when the cAMP-activated protein kinase This occurs when the cAMP-activated protein kinase

enters the enters the nucleusnucleus of the sensory cell, and activates of the sensory cell, and activates CREB (cAMP Response Element Binding protein) to CREB (cAMP Response Element Binding protein) to trigger trigger protein synthesisprotein synthesis. This leads to formation of a . This leads to formation of a variant of the same kinase (cAMP-PK), which is variant of the same kinase (cAMP-PK), which is constitutively activeconstitutively active, without the need for cAMP. The K+ , without the need for cAMP. The K+ channel will then be constantly inhibited. At the same channel will then be constantly inhibited. At the same time, genes for the synthesis of time, genes for the synthesis of active-zone proteinactive-zone protein are are promoted, causing increase of the effective synaptic promoted, causing increase of the effective synaptic area. This then is a form of area. This then is a form of long term memorylong term memory, and , and illustrates how a short term effect can be converted illustrates how a short term effect can be converted eventually into a long-term change, in which protein eventually into a long-term change, in which protein synthesis is required for the transition.synthesis is required for the transition.

Anterograde AmnesiaAnterograde Amnesia

• Inability to form new memories.Inability to form new memories.

• Selective memory deficit resulting Selective memory deficit resulting predominantly from brain damage.predominantly from brain damage.

• Memories prior to the incident are Memories prior to the incident are largely spared.largely spared.

• Memory for skills or habits are often Memory for skills or habits are often spared as well.spared as well.

Characteristics of AACharacteristics of AA

• Memory lapses may be triggered by Memory lapses may be triggered by nervous or upsetting environmentsnervous or upsetting environments

• Stuck in a previous time period in Stuck in a previous time period in own lifeown life

• Most carry on lives normally and Most carry on lives normally and happily, until reminded of their happily, until reminded of their deficit by others or out of place deficit by others or out of place objects or activities.objects or activities.

Hollywood Anterograde Hollywood Anterograde AmnesicsAmnesics

• Finding Nemo (2003)Finding Nemo (2003)

• Memento (2001)Memento (2001)

• 50 First Dates (2004)50 First Dates (2004)

Clinical AAClinical AA

• The infamous Patient H.M. (Bilateral The infamous Patient H.M. (Bilateral Temporal Lobectomy)Temporal Lobectomy)

• Oliver Sack’s Oliver Sack’s Lost Mariner: Lost Mariner: Jimmie G. Jimmie G. (Korsakoff’s Type)(Korsakoff’s Type)

• Oliver Sack’s William Thompson Oliver Sack’s William Thompson (Korsakoff’s Type with much (Korsakoff’s Type with much confabulation)confabulation)

• Oliver Sack’s Stephen R. (Korsakoff’s Oliver Sack’s Stephen R. (Korsakoff’s Type)Type)

AA and Alternate States of AA and Alternate States of ConsciousnessConsciousness

• He screams with terror and confusion, and He screams with terror and confusion, and Sacks admits there is nothing that can be Sacks admits there is nothing that can be done to help him, for like all other done to help him, for like all other anterograde amnesics, he screams "for a anterograde amnesics, he screams "for a past which no longer exists" (The Man Who past which no longer exists" (The Man Who Mistook His Wife For a Hat: p.42).Mistook His Wife For a Hat: p.42).

•Living an existence that is not realLiving an existence that is not real•Never having any ties to reality, Never having any ties to reality,

which consists of timewhich consists of time

Memory is ConsciousnessMemory is Consciousness

• You have to begin to lose your memory, if You have to begin to lose your memory, if only in bits and pieces, to realize that only in bits and pieces, to realize that memory is what makes our lives. Life memory is what makes our lives. Life without memory is no life at all…Our without memory is no life at all…Our memory is our coherence, our reason, our memory is our coherence, our reason, our feeling, even our action. Without it, we are feeling, even our action. Without it, we are nothing…(I can only wait for the final nothing…(I can only wait for the final amnesia, the one that can erase an entire amnesia, the one that can erase an entire life, as it did my mother’s…)life, as it did my mother’s…)

-Luis Bunuel-Luis Bunuel

SUMMARYSUMMARY

• Current autobiographical memories Current autobiographical memories form sense of enduring self?form sense of enduring self?

• As Siegel concluded, neurotransmitters As Siegel concluded, neurotransmitters control consciousness……the fact that control consciousness……the fact that serotonin and ACh are altered suggests serotonin and ACh are altered suggests that memory alteration correlates with that memory alteration correlates with an altered state of consciousness.an altered state of consciousness.

REFERENCESREFERENCES

• Brandt, Ralph & Benedict, Ralph H. B., (1993) Assessment Brandt, Ralph & Benedict, Ralph H. B., (1993) Assessment of Retrograde Amnesia: Findings With a New Public Events of Retrograde Amnesia: Findings With a New Public Events Procedure. Procedure. NeuropyschologyNeuropyschology, 7:217-227, 7:217-227

• McNaugh, J. L. (1966). Time-dependent processes in McNaugh, J. L. (1966). Time-dependent processes in memory storage. memory storage. ScienceScience 153, 1351-1358 153, 1351-1358

• Duncan, C.P. (1949). The retroactive effect of electroshock Duncan, C.P. (1949). The retroactive effect of electroshock on learning. on learning. Journal of Comparative and Physiological Journal of Comparative and Physiological PsychologyPsychology, 42, 3244. , 42, 3244.

• Meeter, Martijn & Murre, Jaap M. J., (2004) Consolidation of Meeter, Martijn & Murre, Jaap M. J., (2004) Consolidation of Long-Term Memory: Evidence and Alternatives, Long-Term Memory: Evidence and Alternatives, Psychology Psychology BulletinBulletin, 130:843-857, 130:843-857

• Clark, Broadbent, Zola, & Squire (2002). Anterograde Clark, Broadbent, Zola, & Squire (2002). Anterograde amnesia and temporally graded retrograde amnesia for a amnesia and temporally graded retrograde amnesia for a nonspatial memory task after lesions of the hippocampus nonspatial memory task after lesions of the hippocampus and subiculum, 4663-4669.and subiculum, 4663-4669.