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THE ADVANTAGE OF HAVING BAD MEMORY IS THAT YOU
CAN ENJOY GOOD THINGS FOR THE FIRST TIME SEVERAL
TIMES.-FRIEDRICH NIETZSCHE
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RETROGRADE AND ANTEROGRADE AMNESIA

• Ellie Moradi
• Colin Schwartz
• Chris Yco
• Melissa Bergh

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RETROGRADE AMNESIATHE UNDERLYING CAUSE
PHYSIOLOGY

• Inability to access memories prior to damage
• Often associated with neurodegenerative diseases
  such as Alzheimers Disease
• Other causes include trauma, tumors,
  cerebrovascular accident (aneurysm),
  encephalitis, chronic alcohol use, and hypoxia
  (lack of oxygen)

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HIPPOCAMPUS
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MEDIAL TEMPORAL LOBE
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Physiology Causes Contd.

• Hippocampal damage
• Hippocampus important for episodic and
  declarative memory
• Damage makes it difficult to recall memories
  prior to damage
• Retrograde amnesia is both extensive and ungraded
  when damage is limited to hippocampus
• Damage does not interfere with learning new
  skills however

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Physiology Causes Contd.

• Medial Temporal Lobe damage
• The sparing of remote memory after damage shows
  that the importance of the medial temporal lobe
  structures for memory gradually diminish.
• Often damage is done to the knowledge stores in
  the MTL affecting the ability to recollect
  memories or information regardless of when it
  occurred or was learned

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RELATION TO ALTERED STATES OF CONSCIOUSNESS

• Memories and past events are contributing factors
  to being an individual
• No studies have shown a complete loss of self
• The individual adapts to the loss of memories

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Characteristics of RA

• Ribot gradient
• The tendency to lose new memories more so than
  old memories
• Span of loss unique, difficult to pinpoint it
• Memory loss
• Retain autobiographical, semantic, procedural,
  general knowledge
• Lose episodic (Brandt Benedict 1993)

• Trevor Rees-Jones (August 1997)

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What can RA tell us about memory?

• Memory-Consolidation Theory (McGaugh 1966)
• New memory has to be consolidated and if
  interrupted leads to RA
• Classical evidence amnesia inversely related to
  the age of the memory (Duncan 1949)
• Problems RA recovery, delayed-onset RA and RA
  for long-term memory (Krickett Carpenter)

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What can RA tell us about memory?

• Multi-trace theory (Nadel et al 2000)
• Hippocampus responsible for encoding and
  retrieving all episodic memory independent of its
  age and thus damage randomly causes deficits.
• Old memories well encoded but can have retrieval
  problems.
• Evidence? Ribot gradients only found in partial
  lesions of hippocampus in rats.
• No real evidence. If you can figure out a way to
  test this, let me know.

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What can RA tell us about memory?

• Semanticization (Cermak 1984)
• All memories start out as episodic and through
  over-learning becomes semantic which is
  independent of hippocampus.

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In concluding RA

• Should old memory amnesia be considered with RA?
• No studies to my knowledge comparing brain areas
  involved in new and old memory RA
• No consensus about RA cause

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RA and ASC

• Sense of self endures in RA
• Theoretically if Ribot gradient went ad infinitum
  would forget about self?
• In Semantization, if all memory starts out
  episodic then awareness externally is episodic
  and semantic internally

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ANTEROGRADE AMNESIA

• Anterograde amnesia is a selective memory
  deficit, resulting from brain injury.

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CAUSES OF INJURY

• Stroke
• ischemic stroke, in which a small blood clot
  becomes wedged in one of the tiny blood vessels
  supplying the brain, blocking the flow of blood.
  This blood clot may have formed in the brain, or
  it may have formed elsewhere, broken free, and
  traveled through the blood stream to reach the
  brain
• Aneurysm
• An aneurysm is a small local bulge in the wall of
  a blood vessel, usually an artery. Normally,
  blood vessels operate like pipes, carrying blood
  throughout the body to cells which depend on this
  supply for oxygen and nutrients.

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AREAS OF INJURY

• The first, and most well-studied, is the
  hippocampus.
• Hippocampus is seen as the gateway through which
  new information must pass before being stored
  into long term memory.
• Once this is damaged, it is almost impossible to
  create new memories.

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INJURY CONTD.

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

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Anterograde Amnesia

• Inability to form new memories.
• Selective memory deficit resulting predominantly
  from brain damage.
• Memories prior to the incident are largely
  spared.
• Memory for skills or habits are often spared as
  well.

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Characteristics of AA

• Memory lapses may be triggered by nervous or
  upsetting environments
• Stuck in a previous time period in own life
• Most carry on lives normally and happily, until
  reminded of their deficit by others or out of
  place objects or activities.

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Hollywood Anterograde Amnesics

• Finding Nemo (2003)
• Memento (2001)
• 50 First Dates (2004)

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Clinical AA

• The infamous Patient H.M. (Bilateral Temporal
  Lobectomy)
• Oliver Sacks Lost Mariner Jimmie G.
  (Korsakoffs Type)
• Oliver Sacks William Thompson (Korsakoffs Type
  with much confabulation)
• Oliver Sacks Stephen R. (Korsakoffs Type)

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AA and Alternate States of Consciousness

• He screams with terror and confusion, and Sacks
  admits there is nothing that can be done to help
  him, for like all other anterograde amnesics, he
  screams "for a past which no longer exists" (The
  Man Who Mistook His Wife For a Hat p.42).
• Living an existence that is not real
• Never having any ties to reality, which consists
  of time

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Memory is Consciousness

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

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SUMMARY

• Current autobiographical memories form sense of
  enduring self?
• As Siegel concluded, neurotransmitters control
  consciousnessthe fact that serotonin and ACh
  are altered suggests that memory alteration
  correlates with an altered state of
  consciousness.

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REFERENCES

• Brandt, Ralph Benedict, Ralph H. B., (1993)
  Assessment of Retrograde Amnesia Findings With a
  New Public Events Procedure. Neuropyschology,
  7217-227
• McNaugh, J. L. (1966). Time-dependent processes
  in memory storage. Science 153, 1351-1358
• Duncan, C.P. (1949). The retroactive effect of
  electroshock on learning. Journal of Comparative
  and Physiological Psychology, 42, 3244.
• Meeter, Martijn Murre, Jaap M. J., (2004)
  Consolidation of Long-Term Memory Evidence and
  Alternatives, Psychology Bulletin, 130843-857
• Clark, Broadbent, Zola, Squire (2002).
  Anterograde amnesia and temporally graded
  retrograde amnesia for a nonspatial memory task
  after lesions of the hippocampus and subiculum,
  4663-4669.