Multi-Store Memory Model

• memory 


  the coding, storage and retrieval of information about events that have happened in the past - includes STM and LTM
• coding

  the form in which information is represented / stored in memory e.g. visually, semantically, acoustically
• capacity


  the measure of how much information can be held in our memory - often held in 'bits'
• duration

  the length of time which memory can be stored
• Sensory Register (SR)

  automatic response to the reception of sensory information
• Short term memory

  present conscious experience where information is processed from the SR through attention and rehearsal
• Long term memory

  information can be permanently stored and there are different types of long term memory e.g. procedural, semantic, episodic
• Multi-store memory model

  sensory register - (attention) -> short term memory - (elaborative rehearsal) -> long term memory - ( retrieval ) -> short term memory
• Sensory register coding


  it processes information from the sensory organs; information is stored in an unprocessed form - modality specific
• echoic store

  for auditory information

  remember by: echo = hear
• iconic store

  for visual information

  remember by: i = eye
• haptic store

  for tactile (touch) information

  remember by: ha = hands
• olfactory store

  for smells
• Crowder (1993) research

  the echoic store holds information for 2-3 seconds

  the iconic store holds information for a few milliseconds

  = therefore different stores have different durations
• Sensory register capacity

  a very large capacity; pieces of information are in their original forms and are highly detailed
• Sensory register duration

  limited duration of 250 - 500 milliseconds; however different stores' information decays at different rates
• Short term memory coding

  mainly acoustically = heard
• Baddeley (1966) procedure

  75 participants divided into 4 groups presented with one of four word lists and repeated 4 times

  testing STM - list with original words in wrong order = must rearrange

  testing LTM - same procedure; 20 minute interval before retrieval
• Baddeley (1966) lists

  List A = acoustically similar words

  List B = acoustically dissimilar words

  List C = semantically similar words

  List D = semantically dissimilar words
• Baddeley (1966) findings 


  (STM) list A performed the worst = 10% recall as similar sounding words were confused; other lists had 60-80% recall

  (LTM) list C performed the worst = 55% recall as similar meaning words were confused; other lists had 70-85% recall
• Short term memory capacity

  limited capacity of 7 + / - 2 items

  Miller (1956):

  participants did the digit span technique to investigate STM capacity; found people recall numbers better than letters 7 is the magic number
• chunking 


  individual pieces of information are grouped into larger units so take up less space in the STM
• Short term memory duration

  limited duration of around 30 seconds
• Peterson and Peterson (1959) procedure 


  24 university students presented with a list of trigrams to recall

  time interval between the presentation of each trigram and recall varied

  ppts had to count backwards in 3s or 4s until told to stop = time intervals were 3 6 9 12 15 and 18 seconds
• Peterson and Peterson (1959) findings

  90% of trigrams were recalled after a 3 second interval

  2% of trigrams were recalled after a 18 second interval

  = therefore information remains in the STM if verbal rehearsal is prevented
• Long term memory coding

  information is processed semantically - e.g. Baddeley (1966) study

  however; music is stored acoustically
• Long term memory capacity

  unlimited potentially; but information can be lost via decay or interference
• Clive Wearing case study

  hippocampus was destroyed by a viral infection

  • unable to lay down long term memories
  • he could play the piano and sight read

  = procedural memory was intact -> suggesting separate stores for the STM and LTM
• Long term memory duration

  memories can last for a lifetime; longer duration of memories when they are originally well coded - but doesn't need to be rehearsed continually to be maintained
• Bahrick et al (1975) procedure

  392 graduates shown photos from a high school yearbook

  recognition group = given a list of names must select who

  recall group = must name people in each photo
• Bahrick et al (1975) findings

  recognition condition: 90% accuracy 14 years after graduation; 60% accuracy after 47 years

  recall condition: 60% accuracy 7 years after graduation; less than 20% accuracy after 47 years
• elaborative rehearsal 


  the transfer of information between STM and LTM
• primary effect

  a cognitive bias referring to an individual's tendency to better remember the first piece of information received
• recency effect 


  a cognitive bias referring to an individual's tendency to better remember the last piece of information received
• H.M (Milner, 1966) case study 


  hippocampus was removed

  • could no longer form long term memories
  • could acquire new skills = procedural memory still intact

  = suggests there is a separate STM and LTM store
• Multi store memory model strengths

  evidence supports the separate stores - case studies; further evidence from laboratory studies e.g. Glanzer and Cunitz (1966)
• Glanzer and Cunitz (1966)

  found that participants could better recall words from the beginning or end of a list = serial position effect

  = therefore supports idea of separate STM and LTM
• Multi store memory model limitations

  doesn't explain processes of coding; Elaborative rehearsal may not be the only way to transfer information from the STM to the LTM e.g. flashbulb memories; reductionist; working memory model is more detailed and comprehensive;