MSM of memory

• Atkinson & Shiffrin (1968) proposed the multi-store model of memory which suggests that the flow of information through the memory system is linear
• The STM & LTM are unitary stores.
• The MSM is like an information processing model with input, process and output.
• Information enters through the senses into the sensory store.
• the sensory register has unlimited capacity
• the duration of the sensory register is 0.25-0.5 seconds and information decays rapidly
• information in the sensory register can be encoded in any format
• Sperling (1960)

  • showed participants a grid of digits to recall
  • found existence of sensory register and sensory memory cannot hold information for long & it decays rapidly here.
• sensory register constantly receives information from the senses, but most of this receives no attention and decays. If information is given attention, it is transferred to STM
• STM has a duration of 18-30 seconds
• STM has a limited capacity of 7 + or - 2 items
• STM mostly encodes information acoustically
• If information is not rehearsed, it is lost through displacement or decay
• Maintenance rehearsal is the process of verbally or mentally repeating information which allows the duration of STM to be extended
• continuous rehearsal renews the information making it a stronger memory when transferred to LTM.
• Information is forgotten if maintenance rehearsal doesn't occur
• if information in STM is rehearsed, it is transferred to LTM
• LTM has potentially unlimited capacity and unlimited duration
• information in LTM is mainly semantically encoded - the information has meaning
• information can be recalled from LTM back into the STM when needed.
• Murdock (1962)

  • ppts presented with lists of 10-40 words, one at a time
  • ppts asked to recall words
  • words at the end of the list were recalled first as they were still in STM (recency effect)
  • words at beginning of list recalled well as they were rehearsed & in LTM (primary effect)
  • evidence of separate STM & LTM stores
• A limitation of MSM is that it is over-simplified. Evidence suggests there are multiple STM & LTM stores. Tulving (1985) argued there are different LTM stores - semantic, episodic and procedural memory. This is a limitation as it contradicts the MSM and the claim the stores are unitary when it is broken into several components.
• A limitation of MSM is that research into duration of STM has low ecological validity. Peterson & Peterson (1959) used nonsense trigrams 'XNW' to investigate STM duration which has little resemblance to items learned in real life. this is problematic as research may not be generalisable to other situations
• A strength of MSM is that it provides a good understanding of structure & process of STM. This model allows researchers to expand and conduct experiments to improve on the model to make it more valid. This is beneficial as the model is influential and has generated a lot of research into memory
• A strength is supporting evidence. Murdock (1962) found evidence for separate LTM & STM stores due to primary and recency effects. This supports MSM because it provides evidence for separate STM & LTM stores with different capacities and durations