THE MODAL MODEL
ATKINSON AND SHIFFRIN, 1968
Sensory
input
Information
Store
Short Term
recode
rehearse
Memory
(STM)
Long Term
Memory
retrieve
(LTM)
Evidence in support of the
Sensory Information Store
* Sperling’s (1960) Partial Recall Effect
- suggests at sensory storage level,
ALL information is available.
* Neisser (1964) and Plomp (1967)’s Masking
Effects
- quantify the very short duration of visual and
acoustic information in the sensory store.
Evidence in support of a
STM/LTM distinction
* Serial Position Effect
* Differences in Storage Capacity
* Differences in Retrieval
* Neurological Evidence
Evidence in support of a
STM/LTM distinction
* The Serial Position Effect
primacy
recency
Recall
First
Middle
ORDER OF WORDS
Last
Serial Position Effect
Evidence for and against
* Effect of distraction (Postman & Phillips, 1965)
- suggests persistence of STM information, and
therefore recency effect, relies on rehearsal
* Effect of inter-item time (Glanzer & Cunitz,
1966)
- suggests transfer of information from STM to LTM
depends on rehearsal
** Effect of rehearsal on recall (Craik & Watkins,
1973)
- surprise test for all F-words in a controlled list suggests
that amount of rehearsal does not predict likelihood of
recall
Evidence in support of a
STM/LTM distinction
Differences in Storage Capacity:
STM = limited
LTM = unlimited
STM
loss of information is due to displacement
LTM
loss of information is due to interference
** STM capacity is hard to quantify
** STM capacity shows interference effects from LTM
- casts doubt on the independence of STM and LTM
stores
Evidence in support of a
STM/LTM distinction
Differences in Retrieval:
STM = exhaustive search
LTM = guided parallel search
STM = shows set size effect (Sternberg)
LTM = shows no set size effect
**LTM retrieval can show set size effect too
(Anderson, 1983)
- suggests that STM and LTM retrieval may not be so
different
** STM retrieval can be affected by what is being
retrieved (Cavanagh, 1972)
- suggests that STM retrieval is not just a matter of the
number of things to search exhaustively
Evidence in support of a
STM/LTM distinction
Neurological Evidence:
Patients HM and KF demonstrate a double-dissociation
of STM and LTM:
HM shows damaged LTM but intact STM
KF shows damaged STM but intact LTM
** Modal model would predict no new learning in KF
- evidence to the contrary suggests that the modal
model may be too simplistic.
Summary
 The modal model as one of the most influential
modern approaches to human memory
 Memory as a multi-store system
 A model capable of guiding predictions and
enquiry
 A model supported by early empirical research
 A good start but ultimately too simplistic