Summary: Iconic Memory

• Capacity: Very large

• Duration: Very short

• Transfer: Readout to STM

• Loss: Phenomenon of backward masking (and its necessity!)

A Multi-store model of memory

• Benefits and limitations

• First memory: sensory store

• Next: Short term memory

Short term memory

• Current contents of memory

• Fundamental bottleneck in processing

• Multiple interpretations

• Capacity

• Duration

• Transfer

• Loss

Basic Operations of STM

• How things enter it

• How things stay in it.

• How we search for things within it.

• How things leave it

Peterson & Peterson: Decay

Waugh & Norman: Interference

Sternberg: Memory scanning

STM-WM (an alternative view)

• Another way of looking at it (STM vs Working Memory) (Baddeley)

• The "bottleneck" issue and an example or two.

• Beating the limits--the work of Chase and Ericcsson: chunks & retrieval structures.

• Finally, how do things move on--elaborative rehearsal

Baddeley: Model of Working Memory

Chase, Ericcsson & Staszewski: Retrieval Structures

Moving on: LTM

• Issues include – How things move on into LTM– Size of LTM– Is LTM “permanent”?– Memory formation impairment

Permanence of LTM• Work of Wilder Penfield• Size of LTM (on assumption of permanence)

– 100,000,000,000 neurons x 10,000 connections = 1015

– Input: time per percept 150 msec x 70 years x 104 bits per percept x 70 years = 1014 bits

– Optic nerve capacity107 bits per second x 70 years = 1016 bits.

– Pragmatic est. 100,000 words + 10,000 pictures + 75,000 chess patterns + 1000’s of episodes = 106

– But some argue that we forget most of what we input!

Earned an A grade- green, C grade- red (Study Hard!)

Long Term Memory Can be Long-term!

Most Famous Memory: HM

• Retrograde amnesia vs anterograde

• Declarative (semantic + episodic) vs procedural distinction in memory type

• How does this occur? –hippocampus and overlying cortical damage

Memory formation environmental effects

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Memory operations in thinking:single/multiple codes?

Response -> Stimulus

Pointing Vocal

Diagram 28.2 11.3

Sentence 9.8 13.8

Collins & Quillien Experiment

John Anderson (CMU) ACT Model