outline and evaluate the multi-store model of memory (essay)

first paragraph (MSM assumptions)

The MSM model assumes that memory comprises 3 stores: Sensory register, STM & LTM. Information flows in a linear fashion between these 3 separate stores. Sensory memory has a large capacity but very short duration, and information is encoded as visual (iconic store), acoustical (echoic store) or tactile (haptic store) information. STM has a capacity of 7+ 2 items or 'chunks' of information and a duration of less than 18 seconds; it encodes mainly acoustically. If information is adequately rehearsed, via prolonged rehearsal, then it passes into the LTM. LTM has an unlimited capacity & duration and encodes mainly semantically. Forgetting is by displacement in STM & decay or interference in LTM.

second paragraph (evidence for iconic sensory memory store)

Evidence for iconic (visual) sensory memory store comes from the observations that we are able to see a cartoon as a continuous visual image (rather than a series of unconnected still images). This is because our iconic sensory store can still remember the first image in the series by the time that we reach the next image.

third paragraph (sensory memory is essential)

Sensory memory is essential - without it we would see all stimuli as an incomprehensible series of unconnected pieces of information. Also, sensory memory helps us pay attention to particular stimuli

fourth paragraph (baddeley 1966 experiment and findings)

Baddeley (1966) also supported the MSM by showing that STM and LTM were separate stores that encode differently. He presented pps with a list of 5 words that were acoustically similar and a list that were acoustically dissimilar and tested recall immediately. Pps were better able to recall acoustically dissimilar words because the similar ones caused acoustic confusion. He concluded that STM must encode acoustically. He also presented lists of 10 words- either semantically similar or semantically dissimilar. Pps could recall (after a 20 minute wait) the semantically dissimilar words better. He thus concluded that they suffered sematic confusion with the similar words and thus LTM encodes semantically.

fifth paragraph (how experiments provided strong evidence and case study)

These experiments provide strong evidence to support the idea that there are separate stores to memory. Other evidence for this comes from studies using brain scans that show that different parts of the brain are used during STM and LTM tasks. Also, brain damage may affect either STM or LTM - again showing that these are separate stores. One example of this is HM who had his hippocampus removed (to treat epilepsy). He had an intact STM but could not form new episodic LTM. As one store was damaged but not the other this supports the idea that they are separate stores.

sixth paragraph (weakness - oversimplification)

The chief weakness of the MSM is that seems to be an oversimplification e.g. the MSM fails to explain why certain types of information are recalled more effectively than others e.g. emotional memories and flashbulb memories can be stored without rehearsal (which is considered essential by the MSM). It also doesn't consider different types of rehearsal i.e. elaborative rehearsal (linking new information to old) may be more effective than prolonged rehearsal.

seventh paragraph (weakness - LTM unitary store - case study)

MSM also states that LTM is a unitary store, but case studies such as Clive Wearing show that there are three parts to LTM. Clive had his episodic LTM damaged (and could not remember events) but he could still play the piano as he had an intact procedural LTM and he still knew what things were, so his semantic LTM was intact. MSM does not account for different types of LTM so ethe model is limited.

eighth paragraph (weakness - elaborative rehearsal and case study)

The MSM model also doesn't explain why elaborative rehearsal (linking new information to existing knowledge) can be a lot more effective than simple rehearsal. Finally, there is now plenty of evidence that STM is not a unitary store. The case study of KF demonstrates this because he could not remember digits that were read to him (only acoustic encoding) but he could remember them if he read them himself (visual and acoustic encoding). This shows that there is also a visual element to STM that is not included in this model.