multi store model of memory Flashcards
what is the multi store model of memory
an information processing model proposed by atkinson and shiffrin
what does the MSM show
it shows memory as a flow of information through a system. this is linear so it flows in one direction and is passive so each store holds on to that information
what are the three stores of the MSM
the sensory register
short term memory
long term memory
what do the terms coding, capacity and duration refer to
coding = different ways to store information
capacity = how much information can be stored
duration = how long the information can be stored for
what does the sensory register do
it collects info detected by sense neurons which is received by the brain
what is the coding of the sensory register
it is modality specific which means it depends on each sense organ
five different sense organs and its coding
iconic (visual)
haptic (touch)
gustatory (taste)
olfactory (smell)
echoic (sound)
what is the capacity of the sensory register
it is unlimited. this is because it has to contain all sense impressions for all senses. it holds unprocessed information. the brain is constantly receiving sense impressions we are not aware of
what is the duration of the sensory register
it is short (250 milliseconds). this is because so much info is held that it cannot be retained for so long
what goes to short term memory
information from the sensory register that is paid attention to. any info not paid attention to is lost
what is short term memory
information held here is used for immediate tasks. it is the information recieved by paying attention. repetition keeps information here
what is the coding of STM
information arrives in original format and recoded in a form easy to deal with (visual acoustic and semantic) main coding is acoustic (sound) for e.g if you need to remember a list you may repeat it over again with inner voice
what is the capacity of STM
7 items +/-2
what is the duration of STM
18-30 seconds so if informations isnt mainatained by subvocal repetition it is lost from STM after that time has passed
how does information go to LTM
by rehearsal
what are the two types of rehearsal
maintenance and elaborative
what is maintenance rehearsal
keeping info in STM by repeating it again and again till it goes to LTM. it is the repetition of info in its original, unaltered form
what is elaborative rehearsal
linking new info to knowledge already in LTM. involves more meaningful analysis (images, thinking, associations)
what happens if info from STM does not pass into LTM
it is lost via displacement or decay
what is the difference between displacement and decay
displacement (new information replacing information already in STM) because of the small capacity of STM new information comes in and already replaces info in STM
decay (lost over time) if info is not rehearsed, it disappears over time
what is long term memory
stores info for lengthy periods of time. it has different kinds of stores - some are eaiser to access than others
what is the coding of LTM
semantic. memory is stored as [art of a set of meaningful connections to other stored info.
what is the capacity of LTM
large, potentially unlimited. limit is not found. brains dont get completely full up with info and cant fit more. maybe we lose the ability to access some info. info can last for up to a lifetime but can be lost through decay and interference.
what is the duration of LTM
unlimited. we can still recall certain childhood events
summarise the different stores of the MSM in terms of coding, capacity and duration
sensory register -
coding = modality specific
capacity = unlimited
duration = 250milliseconds
short term memory -
coding = acoustic
capacity = 7+/-2 items
duration = 18-30 seconds
long term memory -
coding = semantic
capacity = large potentially unlimited
duration = unlimited
what did glanzer and cunitz do
Glanzer and Cunitz asked participants to free recall word lists in any order. they noticed that recall was stronger for words at the start and end of the list. this was known as the serial position effect
what is the serial position effect
it describes how our memory is affected by the position of information in a sequence
what is the primacy and recency effect
words early on in the list were put into LTM because the person has more time to rehearse the words due to the primacy effect
words later on in the list went into STM due to the recency effect
what did the glanzer/cunitz study show about STM and LTM
it showed that they were separate stores holding certain information at certain times
what did sperling show about the capacity of the sensory register
students had a 3 by 4 grid of letters. when presented quickly, they recalled one row. they found that recall for one row was above 75%. this suggests that all rows were contained within capacity of the iconic store so sensory memory is large. with practice, participants became more accurate. this overall shows that STM has capacity of 5-9 items. To recall a whole row, sensory memory would hold all 12 letters. this suggests that the capacity of sensory register is larger than STM
what did baddeley show about the coding of STM
he gave 4 types of word lists = acoustically similiar/dissimiliar and semantically similiar/disimilliar. they either recalled immediately testing STM or after 20 minutes testing LTM. after the immediate testing they found that the worst recall condition was for acoustically similar words. this shows the coding for STM is acoustic as the acoustic similarity of the words caused confusion making it harder to recall
when can it be difficult to recall individual items
it storage system is coded in a similar way
what did baddely show about the coding of LTM
using the same lists he tested the recall of the students after 20 minutes. the worse recall was for semantically similiar words as it caused confusion. this shows that coding for LTM is semantic
what were the aims of the peterson and peterson case study in 1959
they wanted to know if retrieval was needed to transfer long term info from STM to LTM. they also wanted to investigate the duration of short term memory and provide empirical evidence for the multi store model of memory
what was their experiment (P&P)
lab experiment in which 24 psychology students had to recall trigrams (meaningless 3 consonant syllables). to prevent rehearsal participants were asked to count backwards in threes or fours from specified random numbers till they saw a red light appear. when the red light appeared they would have to say the trigram. this would be in intervals of 3,6,9,12 or 15 or 18 seconds
what were the findings of their experiments (P&P)
the longer the interval decay, the less trigrams recalled
participants could recall 80% of trigrams after 3 seconds delay. but after 18 seconds less than 10% of trigrams were recalled correctly
what were the conclusions of the P&P experiment
STM has limited duration when rehearsal is prevented
information is lost from STM using trace decay
STM is different from LTM in terms of duration
this supports the MSM
strengths of MSM
- it gives good understanding of structure and process of STM
- allows researchers to expand on the model
- can do experiments to improve the model and make it valid and to also prove what each individual store does
- model is influential as it generates lots of research into memory
- the large capacity and short duration of the sensory register matches expectations from evolutionary theory taking in as much information as possible but only processing the important information. too much processing slows down reaction speed.
- it may be the only way to clearly measure memory and test its limits
weaknesses of MSM
- experiments testing MSM are highly artificial
- low ecological validity (the findings dont usually apply to envt for e.g the lab envt is unusual and doesnt reflect places we recall)
- not general. they lack mundane realism
- may not apply what we have found in memory in experimental conditions to situations out of experiment
- not able to directly observe
- too simplistic. it suggests that STM and LTM are unitary and passive (just one thing holding on to information)
- lacks face validity (we have LTM that are tastes and smells, capacity of STM isnt fixed, changes with practices)
