Multi-store model of memory

• Definition

  A representation of you memory works in terms of 3 stores called the sensory register, STM and LTM.

  It also describes how information is transferred from one store to another, what makes some memories last and what makes some disappear.
• Sensory register

  • Stimulus from the environment passes into the sensory register.
  • This is a store for each of our 5 senses.
  • Duration: less than half a second
  • Capacity: high
  • Coding: modality specific - two main stores: iconic (visual) and echoic (auditory).
  • Transfer: information is passed to the STM if attention is paid to it.
• STM

  • Duration: 18 seconds without rehearsal
  • Capacity: high
  • Coding: acoustic
  • Transfer: maintenance rehearsal passes information into our LTM.
• LTM

  • Store of information that had been rehearsed for a prolonged time.
  • Duration: up to a lifetime
  • Capacity: unlimited
  • Coding: semantic
  • When we want to recall information, it must be transferred back to the STM by retrieval.
• Strength - research support

  • Studies showing that STM and LTM are different.
  • Baddeley - found that we tend to mix up words that sound similar when we use our STM but we tend to mix up words that have similar meanings when we use our LTM.
  • Peterson & Peterson and Jacobs - studies of capacity and duration.
  • These studies clearly show that STM and LTM are separate and independent memory stores - as claimed by the MSM
• Counterpoint - studies don't use meaningful material

  • MSM may not be a valid model of how our memory works in our everyday life where we have to remember much more meaningful information
• Limitation - more than one STM store

  • Shallice & Warrington studied a client (KF) who had amnesia.
  • STM for digits was poor when the digits were read out loud to him - recall was better when he read the digits to himself .
  • Further studies of KF showed that there could even be another short term memory store for non verbal sounds (eg: noises).
  • This suggests that the MSM is wrong in claiming that there is just one STM store processing different types of information.
• Limitation - more than one STM store

  • Prolonged rehearsal is not needed for transfer to the LTM.
  • Craik & Watkins found that the type of rehearsal is more important than the amount - elaborative rehearsal (when you link the info to your existing knowledge).
  • Suggests that MSM doesn't fully explain how long-term storage is achieved.
• Limitation - Bygone model

  • Lots of evidence that LTM is not one single memory store.
  • One LTM store for memories of facts about the world and one for memories like how to ride a bike.
  • Suggests that MSM is an oversimplified model of memory.