multi store model of memory

• who created multi store model of memory (msm)


  atkinson + shirffrin (1968)
• multi-store model of memory (msm)

  
• consists of both stores and processes
• 3 distinctly sperate stores:

  • sensory memory (sm)
  • short term memory (stm)
  • long term memory (ltm)
• each store is unitary which means it can't be subdivided
• sensory store

  • eyes, ears, nose, fingers, tongue etc + corresponding areas of brain
  • iconic memory- visual
  • echoic memory- auditory

  processes - information is then passed to stm when we pay attention to it in sensory memory

  breif store, duration- less than a second, vast capacity, very little transfered to stm
• structure of sm 


  duration- less than a second

  capacity- vast

  encoding- iconic and echoic
• structure of stm


  duration- 18 to 30seconds (peterson + peterson 1959)

  capacity- 7 +/- 2 (miller), limited (jacob 1887)

  encodes- acoustically (baddeley 1966)
• structure of ltm


  duration- unlimited (bahrick 1975)

  capacity- unlimited

  encoding- semantically (baddeley 1966)
• processes of msm


  • environmental stimuli
  • paying attention
  • displacement/ decay
  • maintenance rehearsal
  • elaborative rehearsal
  • retrieval
• paying attention 


  transfer sm to stm, only if we pay attention, else it decays
• maintenance rehearsal 


  repeating information, over and over until it tranfers into ltm

  (no rehearsal- information becomes displaced)
• elaborative rehearsal 


  give meaning the information.

  type of deeper processing- make semantic.

  from stm to ltm
• maintenance rehearsal (simple)


  repetition
• elaborative rehearsal (simple)


  meaning
• retrieval 


  process of getting information back from ltm to stm so it can be used
• evaluation 


  • brain scans
  • research studies
  • case studies
• brain scans:

  stm task- prefrontal cortex active (beardly 1997)

  ltm task- hippocampus active (squire et. al. 1992)

  supports the idea that stm and ltm are in distinct stores- different areas of brain are active during stm and ltm activities
• research studies

  differences in capacity, duration and encoding (features) functions, shows that stm and ltm have distinct stores- they are separate

  e.g limited vs unlimited (capacity and duration for stm and ltm)
• research studies show distinctively different memory stores in terms of duration, capacity and encoding
• case studies

  • HM- milner (1966), supports msm
  • KF- shallice and warrington (1970), opposes msm
• HM supporting msm


  • hippocampus removed to treat epilepsy
  • stm unaffected
  • could no longer form new or retrieve old ltm

  shows that stm and ltm have distinct stores, as only ltm was affected
• KF opposing msm


  • prefrontal cortex damaged
  • stm with echoic encoding, but iconic encoding was unaffected

  shows that there are seperate components for stm, visual and acoustic.

  stm is non unitary (but msm implies it is unitary)
• inaccuracies (rehearsal vs processing)


  msm focuses on maintenance rehearsal

  craik and tulving- found that elaborative rehearsal (which is deeper and more semantic analysis) needed to transfer to ltm

  the old model only had rehearsal, not elaborative and maintenance
• advantages of msm:

  • evidence from research about the different features of stm and ltm
  • evidence from brain scans
  • case studies such as HM shows seperate stores for stm and ltm
• weaknesses of msm:

  • research into stm and ltm use artificial studies (peterson's 1959 use of trigrams) - undermines the validity of the research supporting msm
  • more than one type of rehearsal, craik and watkins found that elaborative rehearsal was more important for long term storage
  • over-simple structure, presents stm and ltm as unitary. however evidence from KF suggests that stm is not unitary but instead has subsections