multi-store model Flashcards
the multi store model of memory created by
Atkinson and Shiffrin
proposed that memory consisted of
sensory register, short term memory and long term memory
definition of duration, capacity and coding
duration - amount of time information stays in memory store for
capacity - how much can be stored
coding - how the information is processed
two forms of coding in sensory memory
iconic memory
echoic memory
what is iconic memory
visual information from the eyes
things you see, stored as images
what is echoic memory
auditory input from the ears
things you hear, stored as sounds
evidence for capacity of SM comes from
sperling - presented a grid of letters for less than a second
people recalled on average 4 letters
duration of SM
2 seconds (or less)
encoding of short term memory
STM encodes information acoustically - as sounds
capacity of short term memory
5-9 items of information
7+/-2
duration of STM - experiment by
Peterson & Peterson - the trigram experiment
the trigram experiment
24 students recall meaningless three letter trigrams at different intervals
counted backwards from a specific number, until asked to recall the letters to prevent rehearsal
findings of the trigram experiment
the longer the interval, the less accurate the recall
at 3 seconds 80% of trigrams were correctly recalled
at 18 seconds, 10% were correctly recalled
short term memory has a limited duration of
18 seconds
encoding of long term memory - experiment
Baddeley presented lists of 10 short words
some lists were semantically similar, others were semantically dissimilar
tested immediately and after 20 minute delay
results of Baddeleys experiment
after 20 mins they did poorly on the semantically similar words
this suggests encoding in LTM is semantic - by meaning
capacity of LTM
unlimited
atkinson and shiffrin suggested 4 key features of the multi store model
Unitary, Linear, Rehearsal, Passive
definition of unitary, linear, rehearsal and passive
Unitary - there is only one of each store
Linear - a fixed sequence, cannot be leapfrogged
Rehearsal - moving from STM to LTM
Passive - no decision making or problem solving needed
1 general strength of msm
the first model to try and explain memory - stimulated further research eg WMM
Experimental evidence to support MSM
the primary/recency effect
the primary recency effect experiment
read out a list of words to pps and asked them to recall as many as possible
findings of primary recency effect
tended to recall more from the start and the end of the list, and more likely to forget the middle of list
this supports the idea of there being
a separate STM and LTM
explain the ‘primary effect’ and the ‘secondary effect’
primary effect - the words first heard have been rehearsed, recall from our LTM
secondary effect - the words are most recently heard, recall from our STM
BRAIN SCANNING RESEARCH:
- what is active in the brain when: - making a decision - remembering new information
- what does this support
the prefrontal cortex is active when making a decision - using STM
the hippocampus is active when remembering new information - using LTM
this supports the existence of different stores for different memories
2 case study evidence names
HM and KF
HM case study
how does this support the MSM
problems in long term memory after brain surgery removing his hippocampus, his short term memory remains intact
- shows that the stores must be separate as only one part was damaged
KF case study
how does this support the MSM
extremely poor STM after motorbike accident, his LTM was normal
this shows the stores are unitary
case study evidence supports the idea of
separate stores for different types of memory
2 weaknesses of MSM (key features of MSM)
- it is unlikely that memory stores are UNITARY, as evidence from WMM show short term memory has at least 4 stores
- its unlikely that memory is always LINEAR, the STM can sometimes be bypassed - evidence comes from brain damaged patients whos STM destroyed but could still learn new information into LTM
Case Study - as a weakness of MSM
Clive Wearing
explain Clive Wearing
damage to episodic memory - no memory of wedding day, procedural memory still intact - could still play the piano
why is this a problem for MSM
challenges the idea of one unitary store in LTM
weakness of MSM
(validity)
ecological validity
lab setting criticised for lacking ecological validity as they dont reflect real life situations
trigrams and word lists lacks mundane realism
