Multi store model

• multi store model of memory AO1

  Atkinson and Shiffrin - 1968

  memory is made up of 3 components:

  • sensory register
  • short term memory
  • long term memory

  each component has specific coding, capacity and duration
• Sensory register


  capacity: very large

  duration: very limited - 250 m/s

  coding: unprocessed - all 5 senses
• short term memory


  capacity: limited, Jacobs, Miller 7+/-2

  duration: limited, Peterson and Peterson: 20 seconds

  coding: acoustic, Baddely
• long term memory


  capacity: unlimited

  duration: lifetime/years, Bahrick

  coding: semantic, Baddeley
• Key study: Miller 7+/-2


  Aim: investigate capacity of STM

  method: literature review of published investigations into perception and STM from 1930s to 1950s

  results: existing research suggested learning in chunks so STM can cope with seven 'chunks'

  conclusion: organisation/encoding can extend the capacity of STM and enable more information to be stored there
• Miller AO3


  +research support:

  • Jacobs - used a digit span test for sim capacity for numbers and letters - 443 female students from north London, participants needed to repeat back span of digits/letters that were gradually increased
  • average letter span = 7.3
  • average word span = 9.3

  -ignores factors effecting capacity: age can affect capacity: Jacobs STM gradually improves with age
• Key Study: Peterson and Peterson - aim and method


  Aim: investigate how diff STM intervals containing an inference task affect recall of verbally presented items

  Method: 24 male and female uni students, 48 three consonant nonsense syllables (trigrams) as well as cards containing three digit numbers. researcher spell out syllable then a three digit number to prevent repetition of the trigram. red light went on after 3-18sec, and participant had to recall trigram
• Key Study: Peterson and Peterson - result and conclusion


  results: the longer the interval the less accurate the recall. At 3 seconds around 80% of trigrams recalled correctly vs 18 seconds = 10% correct

  conclusion: STM limited duration of 18 seconds, if we are unable to rehearse info it won't be passed on to LTM
• Peterson and Peterson AO3

  -demand characteristics - psychology student encountered MSM before so can change behaviour to assist experimenter

  
  

  -low ecological validity

  
  

  +highly controlled so easy to replicate to test reliability
• Key Study: Bahrick


  Aim: duration of LTM

  method: 392 American uni grads shown photos from high school yearbook and given group of names and asked to match names to photos

  result: 90% correctly match names and faces after 14 years, 67% correctly match after 47 years

  conclusion: can remember certain types of info for almost a lifetime, semantically coded duration at least 47 years
• Bahrick AO3

  -lacks population validity

  +high levels of ecological validity as uses real life memories
• multi store model AO3

  + case study support:

  • Clive wearing - severe amnesia, only remember info for 20-30 seconds but could recall info from his past such as his wife's name - couldn't transfer STM to LTM

  + brain scans - different areas of the brain are active when performing different tasks

  -alternative explanations of - WMM better explains STM