THE MODAL MODEL Sensory Information Store Short Term Memory (STM) Long Term Memory (LTM) input recode rehearse retrieve Atkinson and Shiffrin (1968)

Sperling’s (1960) Partial Recall Effect RNKP M JF BV VL X Partial Recall instruction produces better performance than Total Recall instruction. Effect lasts for up to half a second.

Evidence in support of the Sensory Information Store Sperling’s (1960) Partial Recall Effect - Suggests at a 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 Difference in Retrieval Neurological Evidence

Evidence in support of a STM/LTM distinction The Serial Position Effect

Serial Position Effect Evidence for and against Effect of Distraction (Postman and Phillips, 1965) Suggests persistence of STM information, and therefore recency effect, relies on rehearsal Effect of inter-item time (Glanzer and Cunitz, 1966) Suggests transfer of information from STM to LTM depends on rehearsal Effect of rehearsal on recall (Craik and Watkins, 1973) Surprise test for all B-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 But: 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 BUT LTM retrieval can show a 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. STM – shows set size effect (Sternberg) LTM – shows no set size effect

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 is one of the most influential modern approaches to human memory Memory is a multi-store system The model is capable of guiding predictions and enquiry The model is supported by early empirical research A good start but ultimately too simplistic