Memory Systems

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Memory Systems
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H.M.

• Much of what we know about memory started with
  Henry and patients like him.
• Suffered from temporal lobe epilepsy
• Underwent bilateral temporal lobectomy at 27
• Removal of both hippocampi
• After the surgery Henry demonstrated some
  Retrograde Amnesia, loss of memories of past
  experiences, but more severely from Anterograde
  Amnesia, the inability to form new memories.
• It took Henry about a year to learn his way
  around a new house
• All patients with extensive bilateral damage to
  the temporal lobes have similar impairments

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H.M.

• What did Henry retain after the surgery?
• Declarative memory up until about 3 months
  before the surgery
• Non-declarative memory
• Working memory
• Good command of language and vocabulary
• I.Q. remained unchanged
• What did Henry lack after the surgery?
• Memory for information 3 months prior to the
  surgery
• Ability to form new declarative memories

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Multiple Memory Systems

• Working Memory
• Working memory is a form of memory that keeps
  information for seconds to minutes
• An analogy for working memory is that it is like
  computer RAM, information stays in working memory
  as long as we keep it active its what we are
  currently attending to, and for this reason, many
  feel it is the seat of our consciousness
• Capacity of Working Memory
• We can keep approximately 72 bits of information
  in working memory
• We can increase that capacity by a process known
  as chunking, grouping information into familiar
  chunks, i.e. instead of the letters F, B, and
  I, FBI.

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Multiple Memory Systems

• Alan Baddeley three components of Working Memory
• The Central Executive
• Controls attention
• Imaging studies show that it is in the prefrontal
  cortex
• Many feel that this is the seat of consciousness
• The Phonological Loop
• Brocas Area subverbal rehearsal
• Wernickes area phonological storage
• Imaging studies show that buffer is in
  Association Cortex of left inferior parietal lobe

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Multiple Memory Systems

• Alan Baddeley three components of Working Memory
• The Visual Sketchpad
• Right and left occipital/parietal junction of
  lobes
• Imaging studies show that buffer is in
  Association Cortex of right inferior parietal lobe

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Multiple Memory Systems
Long-term memory
Explicit Declarative Memory
Implicit Non-Declarative Memory (once called
procedural or skill memory, procedural is now a
sub-category)
Semantic Memory for general facts
Episodic Memory for specific facts and events,
usually personal with time/date information