The Multi-Store Model of Memory

Multi-store model of memory - Atkinson & Shiffrin (1968)

A model of memory provides us with what is essentially an analogy of how memory works. The working memory model (WMM) is an expansion of the orginal concept of the multi-store memory model (MSM). The MSM consists of three memory stores, linked to each other by the processes that enable transfer of information from one store to the next.

Sensory Register:

• The place where information is held at each of the senses and the corresponding areas of the brain.
• duration: 1/4 to 1/2 second (< 1 second)
• capacity, potentially unlimited - all sensory experience
• Encoding: sense specific
• If attention isn't paid to the information then it is lost through decay. Attention is the first step in remembering

Short term memory store:

• Information is held in the STM so it can be used for immediate tasks
• duration: 18-30 secs max (Peterson and Peterson) - is in a 'fragile' state and will disappear (decay) relatively quickly if not rehearsed through maintenance rehearsal (which is largely verbal)
• capacity: 7+/- 2 items (Miller)
• encoded phonologically
• stored auditory
• lost information through displacement - if new information enters the STM it displaces the original information in the STM - this is because STM has limtted capacity
• info maintained through light maintenance rehearsal
• if info is understood semantically through deep elaborative rehearsal then info moves into the long term memory store.
• repitition keeps information in the STM but such repitition can create LTM
• Atkinson and Shiffrin proposed a direct relationship between rehearsal in STM and the strength of the LTM
• The more information is rehearsed the better it is remembered - maintainance rehearsal

Long term memory store:

• duration: unlimited
• capacity: unlimited
• encoding: mainly semantic (but can be visual and auditory)
• lost information through interference
• the process of getting information from LTM involves the information passing back through the STM where it becomes available for use

MSM evaluations - supporting studies

• STM - Jacobs (1887) found the average digit span for numbers was 9.3 items whereas it was 7.3 for letters. hence, the type of information can affect the STM. Maybe this was due to 26 letters being more confusing than 9 numbers.
• STM - Miller devised lab-based studies to investigate the number of words that can be recalled and found the magic number (7 +/- 2 items) was almost universal in retention…