SHORT TERM (WORKING) MEMORY

1
SHORT TERM (WORKING) MEMORY

• The phenomenology of STM
• Information-Processing models
• Broadbents p-system (1958)
• Waugh Normans primary memory (1965) (borrowing
  James term)
• Atkinson Shiffrins multistore model (1968)

2
MEMORY STRUCTURES AND PROCESSES INTHE MODAL
MODEL(Atkinson Shiffrin, 1968)
SENSORY REGISTERS
sensory inputs
visual
tactile
auditory
SHORT-TERM STORE (STS) temporary, working
memory
control processes - rehearsal - coding -
decisions - retrieval strategies
LONG-TERM STORE (LTS) permanent memory store
3

• 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)

4
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 doesnt (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)

5
Brain activity and theSTM-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