Multi store model

• Multi-store model (MSM)


  A representation of how memory works in terms of three stores called a sensory register, short-term memory (STM) and long-term memory (LTM). It also describes how information is transferred from one store to another, how it is remembered and how it is forgotten.
• Sensory register


  • The memory stores for each of our five senses, such as vision (iconic store) and hearing (echoic store). Coding in the iconic sensory register is visual and in the echoic sensory register it is acoustic. The capacity of sensory registers is huge (millions of receptors) and information lasts a very short time (less than half a second)
• Short-term memory (STM)


  • For events in the present or immediate past. It is a limited capacity store, can only contain about 7 items. Information is coded acoustically and lasts about 30 seconds unless it is rehearsed.
• Long-term memory (LTM)


  • For events that have happened in the more distant past. It is a potentially permanent memory store for information that has been rehearsed for a prolonged time. Capacity is unlimited and LTM's tend to be coded semantically.
• Cognitive processes


  1. Attention - focusing on stimuli to pass information from sensory store

  2. Maintenance rehearsal - repeating an item to remember it and pass to LTM

  3. Recoding - may be needed between stores

  4. Retrieval - accessing and recovering stored information

  5. Forgetting - decay, displacement, retrieval failure or interference
• The Multi-Store Model of Memory was proposed by Atkinson & Shiffrin (1968)
• The Multi-Store Model now appears simplistic, but it was a necessary first step in the scientific testing of memory
• The Multi-Store Model is based on the features of STM and LTM as well as a third store, the sensory register
• The Multi-Store Model has three components: sensory register (SR), short-term memory (STM) and long-term memory (LTM)
• Each of the three stores has a different capacity, duration and coding
• Information passes from one store to the next in a linear fashion
• STM and LTM are unitary (single) stores
• Rehearsal is needed to pass information from STM to LTM
• Attention


  Used to pass information on from the sensory store
• Maintenance rehearsal


  Used to pass information from STM to LTM
• Recoding


  May be needed between one store and the next
• Retrieval


  Involves accessing and recovering stored information
• Forgetting


  Involves an inability to recall or recognise something that has previously been learnt. There are different types of forgetting that happen in different parts of memory: decay (sensory register and short-term memory), displacement (short-term memory), retrieval failure or interference (long-term memory)
• The primacy effect is when there is better recall of words at the beginning of the list because those words have been rehearsed in STM and transferred in LTM
• The recency effect is when there is better recall of words at the end of the list because those words are still in STM at the time of the recall test
• The words in the middle of the list have tended to be displaced from STM before they had the opportunity for rehearsal
• Murdock (1962) found the primacy-recency effect, supporting the existence of separate STM and LTM stores
• Beardsley found the pre-frontal cortex was active during STM tasks, but not LTM tasks, and Squire found the hippocampus was active when the LTM was engaged, supporting separate STM and LTM stores
• The working memory model updates the STM, showing it as an active store with different components