MODELS OF MEMORY (MSM) — STUDIES

Baddeley 1966 coding in STM and LTM

Participants were given word lists that were acoustically similar or semantically similar and recalled them either immediately or after a delay immediate recall was worse for acoustically similar words showing STM uses acoustic coding and delayed recall was worse for semantically similar words showing LTM uses semantic coding this supports separate STM and LTM stores

Jacobs 1887 digit span

Jacobs tested digit span by reading increasingly long lists of numbers and asking participants to recall them in the correct order the average span was around seven items which supports the idea of a limited capacity short term memory store

Miller 1956 capacity of STM

Through reviewing previous research Miller concluded that short term memory has a capacity of around seven items and that chunking information can extend capacity which supports the MSM idea of a fixed limited STM store

Peterson and Peterson 1959 STM duration

Participants were briefly shown trigrams then given a distraction task counting backwards to prevent rehearsal recall fell rapidly after eighteen to thirty seconds showing short term memory has a very limited duration without rehearsal

Bahrick et al 1975 LTM duration

Participants tested on recognition and recall of classmates many years after graduation recognition remained high even after forty eight years showing long term memory can last a lifetime and supports the MSM idea of a permanent LTM store

Case of H M MSM evidence

H M had hippocampal surgery that left his short term memory intact but prevented formation of new long term memories supporting the idea that STM and LTM are separate systems as described in the MSM

Case of Clive Wearing MSM evidence

Clive Wearing suffered brain damage that destroyed episodic memory but left some short term memory and procedural abilities intact supporting separate memory stores consistent with MSM structure

Craik and Watkins 1973 rehearsal critique

Researchers found that maintenance rehearsal is not enough to transfer information to long term memory and that elaborative rehearsal is more important which challenges the MSM assumption that repetition alone moves memories into LTM