the multi-store model

• define memory

  the capacity to store and retrieve information.
• define msm

  an explanation of memory that sees information flowing through a series of storage systems.
• define sensory register

  a short-duration store holding impressions of information received by the senses.
• define short term memory

  a temporary store holding small amounts of information for brief periods.
• define long term memory

  a permanent store holding limitless amounts of information for long periods.
• define coding, capacity and duration

  coding-the means by which information is represented in memory,

  capacity- the amount of information that can be stored at a given time,

  duration- the length of time information remains in storage
• who was the msm devised by and when

  Atkinson and Shiffrin, in 1968
• the msm model of memory

  1. there are 3 separate unitary memory stores,
  2. it is a linear model
  3. incoming information goes into the sensory register and is briefly stored,
  4. if paid attention to, information is transferred into the stm, which has limited capacity and duration and coding is mainly acoustic,
  5. if rehearsed, memory trace is strengthened and info goes into the ltm where it can last forever, coding here is mainly semantic,
  6. information can be lost at every stage.
• how is information lost in the sensory msm?

  sensory register-majority of information is lost through decay,

  stm- info can be lost through decay or displacement,

  ltm- info can be lost through decay or retrieval failure
• what research did Crowder carry out on the existence and duration of different sr stores in 1993?

  he found that sensory info is coded into different stores. iconic (visual) information lasts for a few milliseconds and acoustic (sound) information lasts for 2-3 seconds
• capacity, coding and duration of the sr, stm and ltm:

  capacity: sr- huge, stm- limited (7 ish), ltm- infinite,

  coding: sr- multi-faceted, stm- mainly acoustic, ltm- mainly semantic,

  duration: sr- 500 milliseconds for visual and 2 seconds for sounds, stm- 18-30 seconds, ltm- lifetime
• how did Sperling research the iconic (visual) sensory memory in 1960?

  • flashed a 3x4 grid of letters onto a screen for 1/20 of a second,
  • as the letters faded he sounded a note (high, medium or low tone),
  • the participants had to recall the letters corresponding to the row indicated by the tone (e.g. high for top, medium for middle and low for bottom)

  he found that most participants could remember the letters in the selected row,

  concluded: iconic memory is large as letters were remembered at a glance and recall rates were high, but this info is lost quickly
• positives and negatives with Sperling/Crowder's research:

  p: they are controlled experiments which can be replicated and they have helped us understand how much information can be processed in the sensory store

  n: it doesn't account for individual people's ability to take info in (e.g. dyslexia) and is very artificial- lacks mundane realism
• what are some ways information is coded in the stm store, and what is the main store?

  visually, acoustically, semantically. The main store is acoustically.
• what was Baddeley's research on coding of the ltm and stm in 1966?


  Baddeley aimed to find whether coding in stm and ltm was mainly acoustic or semantic.

  method: 75 participants were presented with 1 of 4 words lists: acoustically similar, acoustically dissimilar, semantically similar and semantically dissimilar. stm- participants given 5 words form one of the lists and asked to recall these immediately in serial order, ltm- participants were given 10 words from one of the lists and were given a 20 minute interval before asked to recall the words
• what did Baddeley find from his research on coding in the stm and ltm?


  stm: participants performed worst with list A (acoustically similar) with recall of only 10%, the other lists were comparatively good, between 60-80% recall,

  ltm: participants performed worst with list C (semantically similar) with recall of only 55%, the other lists were comparatively good, between 70-85% recall,

  conclusion: stm must rely on acoustic coding and ltm must rely on semantic coding
• strengths and weaknesses of Baddeley's research on coding?

  s: he conducted a well controlled experiment which can be replicated, it clearly demonstrated how we can process info by sound and meaning,

  w: lacks mundane realism, highly likely there is also semantic coding in the stm, may lack ecological validity and there are different types of ltm not included in his research
• what did Miller believe about the capacity of the stm in 1959?


  we can store an average of 7 'chunks' of info (Miller's Magic number 7)
• what research did Jacob's lead on the capacity of stm in 1887?


  method: participants were given increasingly longer lists of numbers and letters and had to recall these aloud in the right order (digit span),

  he found that the average recall was between 5-9 items, numbers were more easily recalled than letters and recall improved with age,

  strengths: gives evidence that stm has limited capacity, has validity as people remember an average of 7 items in real life,

  weaknesses: very artificial (digits are meaningless), lacks mundane realism, stm capacity may be greater than study suggests
• what is chunking?

  grouping information together to give them collective meaning, increasing the capacity of the stm
• what research on the duration of the stm did Peterson and Peterson carry out in 1959?

  they used three-letter long trigrams of consonants, showed them to participants before an interval. In the interval, rehearsal was prevented using the Brown-Peterson technique (counting backward in 3's from a number), until they were told to recall the trigrams,

  they found that after 18 seconds, less than 10% of the trigrams were recalled correctly; stm has a short duration of around 18-30 seconds
• what research did Bahrick carry out on the duration of ltm in 1975?


  he gathered 392 participants and tested them using photo recognition tests and free recall tests on those they went to school with,

  gave them an old school photo and asked them to recall the names of the people, (later gave cues to help match the person to the name- this comes under forgetting)
• what research did Conrad do on coding of stm in 1964?


  participants were presented with a sequence of 6 letters and were then asked to recall these in the right order

  he found that letters with similar sounds (p,d,t) were harder to recall correctly than different sounds (d,o)

  he concluded that coding in the stm was mainly acoustic
• what is ecological validity?

  the extent to which the findings of a research study are applicable to other situations outside of the lab
• what is the primary effect and recency effect?

  primary effect: individual's tendency to better remember the first piece/s of information they encounter, than info later on,

  recency effect: cognitive basis where items that came last are remembered more clearly than those remembered first,

  these are relevant in memory experiment's when recalling words from a list with/without an interval