Multi Store Model

Sensory memory.Information enters through the 5 senses where it stays for only fractions of a second. If attention is paid to it, it will be passed onto the Short term memory store.

Short term memory.Information is encoded acoustically, this memory store is very limited in terms of capacity, it can hold 7+/-2. Information will only stay in this store for 30 seconds without rehearsal.

Long term memory.Information is encoded semantically, it has potentially unlimited capacity and a duration of a life time.

Duration.

Short Term - Peterson and Peterson 1959Testing how long STM lasts without rehearsal. Participants were shown consonant trigrams then asked to count backwards in threes from a specified starting point, then stopped and asked to recall the letters. This was done at different intervals of 3,6,9,12,15 and 18 seconds. After 3 seconds 80% recalled the trigrams correctly were as after 18 seconds fewer than 10% could recall. If rehearsal is prevented information vanishes rapidly from the STM after a max of 30 seconds.

Long term - Bahrick 1975392 graduates from high school in America over a 50 year time period, being shown photographs from their high school year book. For each photo participants had to match faces and a list of names. the results were that 90% were correct after 14 years and after 47 years 60% were still accurate.LTM can last a life time.

Encoding.

Baddeley 1966Exploring the effects of acoustic and semantic encoding in the STM and the LTM.Words in the follow categories were used:Acoustically similar wordsAcoustically dissimilar wordsSemantically similar wordsSemantically dissimilar words.In the STM study participants were ask immediately after presentation to recall in order 5 words.In the LTM study each list of words was extended to 10 and was tested on recall after 20 minutesBaddeley found that STM participants struggled to recall acoustically similar words, whereas the LTM participants struggled with the semantically similar words.From this it was possible to conclude that acoustic is important for short time encoding, while long term encoding focuses on semantic.

Capacity.

Miller 1956Found that capacity of the STM to be limited to 7 items +/- 2.LTM is very large potentially unlimited. However if we can “chunk” information together we can store a lot more information in our short term memory.

Evaluation.

The model has support for its proposal of functional distinction - the idea of being more than one type of memory store. The case study of Clive Wearing who after suffering from a virus cannot form new memories. He does have access to his long term memory however as he remembers how to play the piano and recognises his wife. This supports the idea of the multi store model showing that the short term and long term memory are seperate because it shows that one can function without the other.

The model is oversimplified in terms of process. The multi store model emphasises the role of rehearsal in transferring memories from the short term to the long term memory, however this is not always the case, for example with information we find relevant to us or interesting we do not need to rehearse it for it to become part of our long term memory

The model has face validity, most people experience only being able to remember some things for a few seconds and rehearsal seems to enable memories to be stored for longer, eg rehearsal of a phone number. In that respect the model makes sense.

Atkinson and Shiffrin 1968.

Introduction

Duration studies

Encoding studies

Capacity

Evaluation