multi-store model of memory

• Atkinson and Shiffrin

  • First cognitive explanation of memory
  • MSM describes how information flows through the memory system
  • Memory is made of 3 stores linked by processing (sensory register, short term memory, long term memory)
• sensory register

  • All stimuli from the environment pass into the SR
  • Coding = modality-specific, depends on the sense (visual in iconic, acoustic in echoic etc)
  • Duration = very brief, less than 1/2 a second
  • Capacity = very high
  • main sensory stores = iconic, echoic
• transfer from SR to STM

  • Information passes further into memory only if attention is paid to it (attention is the key process)
• short-term memory (STM)

  • A limited capacity store of temporary duration:
  • Coding = acoustic (based on sound)
  • Duration = about 18 seconds, unless the information is rehearsed
  • Capacity = between 5 and 9 (7±2) items before some forgetting occurs
• transfer from STM to LTM

  • Maintenance rehearsal = occurs when we repeat (rehearse) material to ourselves
  • we can keep information in STM as long as we rehearse it
  • If we rehearse it long enough, it passes into the LTM
• long term memory (LTM)

  • A permanent memory store
  • Coding = mostly semantic (ie in terms of meaning)
  • Duration = potentially up to a lifetime
  • Capacity = potentially unlimited
• retrieval from LTM

  • When we want to recall information stored in LTM it has to be transferred back to STM by a process called retrieval
• Strength = research support showing STM and LTM are different

  • Baddeley = found that we tend to mix up words that sound similar when using our STM (so STM coding is acoustic)
  • But we mix up words that have similar meanings when we use our LTM (which shows that LTM coding is semantic)
  • Supports the MSM’s view that these 2 memory stores are separate and independent
• counterpoint to research support showing STM and LTM are different

  • Despite such apparent support = the studies tend not to use everyday information (eg faces, names)
  • They use digits/letters (Jacobs) or meaningless consonant syllables (Peterson and Peterson)
  • => the MSM may not be a valid model of how memory works in everyday life where memory tends to involve meaningful information
• limitation = evidence suggesting there is more than one STM store

  • Shallice and Warrington = Patient KF had amnesia:
  • STM recall for digits was poor when he heard them but much better when he read them
  • Other studies confirm there may also be a separate STM store for non-verbal sounds (eg noises)
  • => the MSM is wrong to claim there is just one STM store processing different types of information
• limitation = prolonged rehearsal is not needed for STM-LTM transfer

  • Craik and Watkins = argued there are 2 types of rehearsal called maintenance and elaborative
  • maintenance = (amount of rehearsal) is described in the MSM
  • Elaborative rehearsal = needed for long-term storage
  • Occurs eg when you link information to your existing knowledge, or think about its meaning
  • Suggests that the MSM does not fully explain how long-term storage is achieved
• extra evaluation = bygone model

  • MSM was a useful model that explained a lot of evidence at the time (eg differences between STM and LTM)
  • BUT = it has become clear that the MSM cannot account for many research findings (eg amnesia) and oversimplifies the nature of STM, LTM and rehearsal
  • => the MSM was a good starting point for developing more valid models of memory that explain the research evidence better
• The MSM diagram