SHORT TERM (WORKING)
MEMORY
• The phenomenology of STM
• Information-Processing models
– Broadbent’s “p-system” (1958)
– Waugh & Norman’s primary memory
(1965) (borrowing James’ term)
– Atkinson & Shiffrin’s multistore model
(1968)
MEMORY STRUCTURES AND
PROCESSES IN
THE “MODAL MODEL”
(Atkinson & Shiffrin, 1968)
sensory
inputs
SENSORY REGISTERS
visual
auditory
tactile
SHORT-TERM STORE (STS)
temporary, working memory
control processes:
- rehearsal
- coding
- decisions
- retrieval strategies
LONG-TERM STORE (LTS)
permanent memory store
• Characteristics of the short-term
store: the classic period
– Brief duration
• (Peterson & Peterson 1959)
– Limited capacity
• (Miller, 1956)
– Dominance of speech-like codes
• (Conrad, 1964; Baddeley 1966)
– Serial “retrieval” process
• (Sternberg 1966)
– STM Rehearsal consolidates LTM
• (Rundus & Atkinson 1971)
– Forgetting through decay
• (Peterson & Peterson 1959)
– Or displacement
• (Waugh & Norman 1965)
SUPPORT AND PROBLEMS FOR
THE CLASSIC VIEW
• Dissociations in amnesia
– HM, others show STM
LTM failure
– But PV, others learn despite poor STM
• Recency effects in free recall
– Distraction after last word eliminates it
(Glanzer & Cunitz, 1965)
– But distraction after every word doesn’t
(Bjork & Whitten, 1974)
• Primacy effects in free recall
– Strong correlation between rehearsal
and recall (Fischler & Rundus, 1970)
– But this can be decoupled by
‘maintenance” rehearsal (Craik &
Watkins, 1975)
• STM capacity and speech
– Impact of speech on capacity, errors
(e.g., Baddeley, 1966)
– But visual, semantic codes may also
play a role in “STM” tasks (e.g.,
Baddeley & Hitch, 1974)
Brain activity and the
STM-LTM distinction
• Talmi, et al. (2005)
– 12-word lists shown visually
– Test for recognition early vs. late in seq
– BOLD response (fMRI) contrasted
Early
vs
Late:
Early
vs
Control:
So:
LTM retrieval
activates MTL;
STM retrieval
does not