multi- store model of memory Flashcards
who was it created by?
Atkinson and Shiffren (1968)
The 3 MSM stores?
-
what is coding?
- the different information types/formats the brain uses to store memory
what is duration?
- how long information can be held by a store
what is capacity?
- how much information can be held in a store before it is lost
what is the sensory register?
- sensory info coming from the senses is detected and recorded automatically
- all info in STM and LTM is initially gathered by the sensory register
- info passed to the STM by paying attention
coding of the sensory store:
- store depends on the sense that the organ that the information comes from
- iconic: vision
- echoic: sound
- haptic: touch
- it is modality specific
capacity of sensory register:
- very large
- has to contain all the sensory info for everything in that moment
- only info that is paid attention to gets passed onto the STM
duration of the sensory register:
- very short
- low as 250 milliseconds
- bc so much info is held it cant be retained for very long
what is the short term memory?
- receives info from the sensory register by paying attention
how does info from STM get passed to and from the LTM?
- through rehearsal
- maintenance
- elaborative
- info is passed back from the LTM with retrieval
- info can be lost by displacement or decay
what is maintenance rehearsal?
- repeating the info
what is elaborative rehearsal?
- linking the info to info that is already in the LTM
coding of the STM:
- info stored acoustically
capacity of the STM:
- 7 +/- 2 items
- improved by chunking which reduces the amount of overall items
duration of the STM:
18-30 seconds
- can be extended by verbal rehearsal
what is the LTM:
- can be permanently stored
- may be unlimited in the amount of info it can contain
- comes from STM via rehearsal
- to use info from LTM needs to be retrieved to STM
coding of the LTM:
- stored semantically
- in the form of ‘meaning’
capacity of the LTM:
- unlimited amounts of info can be stored
- info can be lost but not because its ‘out of the room’
- info may still be in the LTM just not accessible
duration of the LTM:
- potentially unlimited
- recall of childhood events is normal even for old people
Evidence that LTM and STM are different processes: Glanzer and Cunitz (1966) free recall of words
- asked pp to free recall words in any order
- recall was higher for words first and last
- the first words went into the LTM and the most recent words recalled by the STM
- words in the middle were in the STM but displaced by later words
Evidence for capacity of the sensory register: Sperling (1960)
- pp shown 3x4 grid of letters
- when shown quickly and had to recall one row
- recall was over 75%
- all rows contained within the capacity of the iconic store
- sensory memory is large
Evidence for duration of the sensory register: Sperling (1960)
- when asked to recall all, they could only recall first 4-5 letters
- letters fade from the sensory register before they could be paid attention to and pass in STM
- shows duration is less than 1 second
Evidence for coding of STM: Baddeley (1966) 4x10 word lists to 4 participant groups
- A= acoustically similar
- B= acoustically dissimilar
- C= semantically similar
- D= semantically dissimilar
- immediate recall worse for A
- recall after 2o mins worse for D
- coding is acoustic
- similar sounding words made recall worse
Evidence for capacity of STM: Jacobs (1887) shown list of letters and numbers
- asked to recall the list
- average for letters= 7 and numbers= 9
- capacity is limited
- Miller can be improved by chunking (grouping) reduced number of overall items
Evidence for duration of STM: Peterson and Peterson (1959) 3 letter trigrams
- showed trigrams, asked to count backwards to stop maintenance rehearsal
- after 18 seconds recall was less than 10%
- unless maintained info is only held for around 18-30 seconds
Evidence for coding of LTM: Baddeley (1966) 4x10 word list for 4 pp groups
- A= acoustically similar
- B= acoustically dissimilar
- C= semantically similar
- D= semantically dissimilar
- immediate recall worst for A
- recall after 20 mins worst for C
- coding in LTM is semantic
- C was most diff bc words similar in meaning
Evidence for capacity of LTM: Wagenaar (1968) diary of over 2400 events over 6 years
- when testing the events using cues
- had 75% of one critical detail after 1 year and 45% after 5 years
- sense of remembering the event after 5 years was high at 85%
- shows capacity is large, unlimited
Evidence of duration of LTM: Bahrick (1975) memory of old school friends
- 392 pp aged 17-74 asked names and faces of old school friends
- recall in matching names to faces was 90% after 15 years
- 80% recall after 45 years
- duration is large, limitless
Evaluating the MSM: limitation, experiments used lack external validity
- cognitive experiments are highly artificial and lack external validity
- low ecological validity and not generalisable to more naturalistic situations
- lack of mundane realism as people usually use their memory in more complex ways
Evaluating the MSM: strength, uncover the underlying internal mental structure of memory
- artificial nature of the design of experimental studies is the only way to clearly measure and test the limits of memory
- this uncovers the underlying internal mental structure of memory
Evaluating the MSM: limitation, have to make inferences on the structure
- memory models cannot be directly observed
- researchers have to make inferences based on the behaviour they observed
- inferences could be incorrect
Evaluating the MSM: strength, supported by the evolutionary theory
- large capacity and short duration of the sensory register matches what would be expected from the evolutionary theory
- as much info as possible gathered from the environment
- only important info is processed
Evaluating the MSM: limitation, simplistic
- neither LTM or STM are unitary stores
- there are multiple types of LTM and STM as shown in the WMM
- lacks validity as capacity of STM changes over time
