memory - multi store model Flashcards
who created the multi store model of memory
atkinson and shiffrin
what are the features of the msm
- linear model as information flows in one direction
- passive stores which hold onto to information before being passed on or lost
what are the three stores in the msm
- sensory register
- short term memory
- long term memory
what are the features of each store in the msm
- encoding
- capacity
- duration
what is meant by encoding
the different information formats the brain uses to store memory
what is meant by capacity
how much information can be held in a store
what is meant by duration
how long information is held in the store before it is lost
what happens at the sensory register
information comes in from the senses and is passed onto the stm by paying attention
what is the encoding of the sensory register
the store depends on the sense organ the information comes from so it is modality specific
what is the capacity of the sensory register
it is very large because it has to contain all sense impressions
what is the duration of the sensory register
very short as low as 250 milliseconds
what happens at the short term memory
information is passed on to the ltm by rehearsal. this can either be maintenance which is repeating information or elaborative which is linking to info already in the ltm
what is the encoding of the short term memory
info is stored acoustically
what is the capacity of the short term memory
miller - suggested this is 7 plus or minus 2 however it can be improved by chunking to reduce the number of items overall
what is the duration of the short term memory
short ( 18-30 seconds ) however can be extended by verbal rehearsal
what happens in the long term memory
information is passed back to the stm via retrieval however the info can be lost via displacement ( replaced with new info ) or decay ( lost over time )
what is the encoding of the long term memory
info is stored semantically
what is the capacity of the long term memory
no limit has been found
what is the duration of the long term memory
potentially unlimited as recall of child hood events is normal even for old people
what was glanzer and cuntizs research into stm and ltm
asked participants to free recall a word list in any order
what were the findings of glanzer and cunitzs research into stm and ltm
recall was much stronger for words that were at the start and end of the list
what do glanzer and cunitz findings suggest about stm and ltm
that they are separate stores as the words at the start of the list have entered the LTM and the words and the end have entered the STM
what is sperlings research into the capacity of the sensory register
participants were presented with a 3x4 grid of twelve letters for 1/20th of a second and then had to recall one row
what were sperlings findings on the capacity of the sensory register
recall for a row was over 75%
what do sperlings findings on the capacity of the sensory register suggest
sensory register is large due to all rows being contained within the capacity of the ionic store
what was sperlings further research into the the duration of the sensory register
when participants were asked to recall all the letters, they could only recall the first 4-5 suggesting that the other letters had faded from the sensory register before they could be paid attention to and passed onto to the stm suggesting that duration is less than a second
what was baddleys research into the coding of stm and ltm
gave 4 10 word lists to participants:
A - acoustically similar
B - acoustically dissimilar
C - semantically similar
D - semantically dissimilar
what were the findings of baddleys research into the coding of stm and ltm
immediate recall was worst for list A and recall after 20 mins was worst for list C
what do baddleys findings into the coding of stm and ltm suggest
stm - coding is acoustic as recall for list A was the worst since the similar sounds were confusing
ltm - coding is semantic as recall for list C was the worst due to similar meanings confusing recall
what was jacobs research into the capacity of the STM
participants were presented with lists of letters of numbers which they then had to recall
what were jacobs findings on capacity of the stm
the capacity for letters was on average 7 items and 9 for numbers
what do jacobs findings on capacity of stm suggest
the capacity of stm is very limited
what was peterson and petersons research into the duration of the stm
showed participants 3 letter trigrams, they then had an interference task to count backwards for a few seconds to stop maintenance rehearsal and then recall
what were peterson and petersons findings on duration of stm
after 18 seconds recall was less then 10%
what do peterson and petersons findings suggest about duration of stm
that unless maintained info is only held in the stm for a few seconds before it dissappears
what was wagenars research into the capacity of ltm
created a diary of over 2400 events over a 6 year period which he had to recall
what were wagenars findings on capacity of ltm
he had 75% recall after 1 year and 45% recall after 5 years
what do wagenars findings on capacity of ltm suggest
the capacity of ltm is very large and potentially limitless
what was bahricks research into duration of ltm
392 participants aged 17-74 were tested on old photographs and names of school friends
what were bahricks findings on duration of LTM
recall in matching names to face 90% after 15 years still 80% after 48 years
what do bahricks findings on duration of ltm suggest
duration of ltm is very large and potentially limitless
what are the strengths of the msm
- the artificial nature designs of the studies may be the only way of clearly measuring memory and testing its limits
- the large capacity and short duration of the sensory register matches what would be expected of evolutionary theory which is that as much info as possible is gathered from the environment but only what is important is processed
what are the weaknesses of the msm
- experiments are often highly artificial which lack in external validity. there is low ecological validity as results collected in a lab may not be generalisable to more naturalistic environments therefore lacking mundane realism as the tasks in study are unlike how people use memory in real life scenarios
- models of the memory cannot be directly observed so researchers have to make inferences based on the behaviour observed during experiments. these are effectively educated guesses which could be incorrect
- later research has demonstrated that neither stm or ltm are unitary stores since there are multiple types of ltm and stm is better described by the wmm
