3 Structures of Memory

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3 Structures of Memory

• Sensory Registers
• very transient, high capacity
• iconic memory
• echoic memory
• Short-term/Working Memory
• transient
• capacity-limited
• Long-term Memory
• relatively permanent
• perhaps unlimited

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Sensory Registers

• Iconic memory
• Visual information is input during brief
  fixations how much information is taken in?
• Span of apprehension is about 7 items
• George Sperling devised the partial report
  technique to show that much more information is
  available but is rapidly lost

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Sensory Registers

• Echoic memory
• Darwin, Turvey Crowder demonstrated an echoic
  memory with partial report
• Shadowing task
• Suffix effect

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Sensory Registers

• Summary
• Our sensory systems initially process very large
  quantities of nonselected information, but most
  of this information is rapidly lost
• What is retained is the very limited information
  to which we have paid attention

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Short Term Memory Dual Store View

• Important features
• Information must go through STM before it is
  stored in LTM
• Time-limited availability
• Capacity limited
• Transfer to LTM depends on time in STM

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Evidence for Dual Store View

• The story of H.M.
• removal of hippocampus to treat epilepsy
• result is anterograde amnesia
• every moment is like waking from a dream
• Short term memory is fine long term memory is
  fine, but no new learning
• Memory Span

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Memory Span

• The amount that can be remembered from a single
  presentation
• memory span is limited to about 7 /- 2 chunks
  (George Miller)
• practice in chunking can extend span
• memory span depends on reading rate (Cavanaugh)

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Memory Span Test

• 2 7 4
• 5 6 1 9
• 7 1 5 9 4 2
• 9 5 7 6 3 2 1 8
• 5 1 6 4 2 9 8 3 7
• 1 7 7 6 2 0 0 1 1 9 9 8 1 0 6 6

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Short-term MemoryOne Store View

• STM is the currently activated portion of LTM
• Semantic structure is important in STM as in LTM
• Loss of activation in STM is part of the same
  loss that occurs for LTM

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Active or Working Memory

• Central Executive, slave rehearsal states
• Rehearsal Slaves
• phonological loop
• verbal rehearsal
• visuo-spatial sketch pad
• spatial/visual rehearsal