Multi-Store Model


Distinction between STM and LTM

Glanzer and Cunitz (1966)

-          Condition 1 free recall from a list of words

-          Condition 2 free recall after distracter task (counting backwards in threes for 30 seconds)

-          Condition 1 produced serial position curve

-          Condition 2 found that distracter task had disrupted recency effect (last list of words recalled poorly)

è Beginning words were rehearsed and thus stored into the LTM, last list of words had no time for rehearsal and thus were displaced.


-          + Highly controlled lab experiment and has been replicated many times

-          + Several trials were done and average was recorded to avoid unrepresentative results

-          - Artificiality means it might not represent how memory works in everyday life

+ refers to supporting the proposed concept

-  Refers to rejecting the proposed concept



Case studies 

Milner (1966) – “HM = STM”

-          HM had a surgery to treat his epilepsy

-          HM was able to recall events in his early life but was unable to remember events 10 years before surgery

-          HM could not learn or retain new information (he’d read a magazine repeatedly without realising he had read it before)

è HM had a normal STM but his LTM now was defective


Shallice and Warrington (1970) – “KF = LTM”

-          KF has brain injury after a motorcycle accident

-          KF was able to learn and recall new information

è KF had normal LTM but his STM was limited to one item


Capacity of STM 

Jacob (1887)

-          Created a method called “The Digit Span Technique” which is used by many psychologists

è Jacobs found that people could recall about seven digits in this immediate serial recall task

Miller (1956) (Supports Jacob) – “7 -/+2 items”

-          Proposed that chunking was the basic unit in STM

-          Believes we can recall 7 +/-2 chunks of information at any one time


-          - Simon (1974) says span is dependent on size of the chunk


Duration of STM

Peterson and Peterson (1959) – “Trigram”

-          Presented participants with consonant trigram (e.g. CXK and LDH ß do not sound the same)

-          Participants were asked to count backwards in threes from a specific number (to stop rehearsal)

-          After intervals of 3, 6, 9, 12 or 18 seconds participants were asked to stop counting backwards and to repeat the trigram

-          Procedure was repeated several times using different trigrams

è Participants were able to recall about 80% of trigrams after 3 second interval without rehearsal but became worse (10% after 18 seconds)

è Concluded that information disappears or decays very rapidly when rehearsal is prevented


-          + Lab experiment and therefore highly controlled

-          + Was repeated to avoid individual differences



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