memory Flashcards
what is the multi-store model of memory?
- atkinson and shriffin’s (1968-1971) MSM describes how info passes through memory system
- suggests memory consisted of 3 stores: sensory register, STM and LTM - STM + LTM being unitary states
- info passes from store to store in linear way + the stores are passive (hold onto info before it is moved on or lost)
what is the sensory register? when does info pass through it?
- stimuli from the environment pass into the register automatically
- part of the memory that comprises of several registers (one for each sense)
- not under cognitive control like LTM + STM
- info only passed on to STM if pay attention
what is the coding, capacity and duration of the sensory register?
- coding in each store is modality specific (iconic = vision/ echoic = sound)
- duration of material in SR very brief - less than half sec
- SRs have very high capacity
what is the STM? the duration of STM like? capacity? encoding?
- a temporary memory store
- coded mainly acoustically
- duration - lasts about 18 secs unless rehearsed
- capacity - 7+/-2 limited capacity store
what is maintenance rehearsal?
- occurs when we repeat material to ourselves over and over again
- can keep info in STM as long as we rehearse it - if rehearse long enough passes into LTM(elebarotive rehearsal)
How is information lost?
- through decay or displacement
what is LTM? what is duration like? capacity? encoding?
- potentially permanent memory store for info that has been rehearsed for prolonged time
- coded mostly semantically (meaningful)
- duration - unlimited
- capacity - practically unlimited
what is retrieval?
according to MSM when want to recall info from LTM has to be transferred back into STM by process called retrieval
one strength of MSM? ev
- support from studies showing LTM and STM are different
- Baddeley (1966) found tend to mix up words sound similar using STMs - but mix up words with similar meanings when use LTMs
- shows STM and LTM separate indep memory stores like MSM claims
counterpoint to strength of MSM (baddeley)? ev
- in everyday life form memories related to useful things - faces names etc
-but many studies supporting MSM use none of these
- words - baddeley
- digits, letters - jacobs
- consonant syllables with no meaning - p&p
- MSM may not be valid model of how memory works in everyday lives when have to remember meaningful info
two limitations of MSM? ev
- evidence for more than one STM store - KF- had amnesia + his STM for digits poor when read out loud to him but much better when read himself - could be another STM for non-verbal sounds - so MSM wrong claiming just one STM
- prolonged rehearsal not needed for transfer to LTM - according to MSM what matters about rehearsal is amount but craik + watkins (1973) found type important - elaborative rehearsal needed for LT storage - PR not necessary
- suggests MSM does not fully explain how LT storage achieved
what is elaborative rehearsal?
when you link the information to your existing knowledge or think about what it means
what is encoding? what are the forms?
- the way information is changed so that it can be stored in the memory
- three main ways info can be encoded
- visual (picture)
- acoustic (sound)
- semantic (meaning)
what is the procedure of Baddeley (1966) study?
- gave list of words to 4 groups of ppts to remember
- group 1- acoustically similar
- group 2- acoustically dissimilar-
- group 3- semantically similar
- group 4- semantically dissimilar
- ptps shown words + asked to recall in order
what were the findings of Baddeley’s study? what do they suggest?
- did task immediately - recalling from STM- did worse with acoustically similar words
- recalled after 20mins from LTM did worse semantically similar words
- findings suggest info is coded acoustically in STM and semantically in LTM
which study is research on coding?
Baddeley (1966)
which studies are research on capacity?
- Jacobs (1887)
- Miller (1956)
what did jacobs (1887) do?
- found out how much info STM can hold at one time by measuring digit span
- ptps presented with a list of letters or numbers which increase as they recall them correctly + then have to recall until they cant anymore
what were the findings of jacobs (1887)
found that mean span for digits across all ptps was 9-3 items and mean span for letters was 7-3
what did Miller (1956) do?
- made observations of everyday practice + noted things come in sevens
- thoughts span of STM about 7+/-2
- also noted that people can recall 5 words as easily as can recall 5 letters - do this by chunking
what studies show research on duration?
- P&P (1959)- duration of STM
- Bahrick et al (1975) - duration of LTM
what did peterson and peterson (1959) do?
- tested 24 students in 8 trials
- each trial the student given a consonant syllable to remember + 3 digit number
- told to count backwards from number to prevent mental rehearsal of syllable
- on each trial told to stop after varying periods of time: 3 secs, 6, 9..18.
what were the findings of P&P (1959)? what do they suggest?
- after 3secs average recall about 80%
- after 18secs - 3%
- findings suggest STM duration may be about 18secs unless verbal rehearsal is done
what did bahrick et al (1975) do?
- studied 392 ptps ages 17-74
- high school yearbooks obtained from ptps or some schools
- recall tested in various ways:
- photo-recognition test consisting of 50 photos some from ptps yearbooks
- free recall test - pfpts recalled all names of graduating class
what were the findings of bahrick et al (1975) ? what do they show?
- ptps tested within 15 years of graduation about 90% accurate in photo recognition
- after 48 years declined to about 70%
- free recall less accurate than rec - 60% after 15yrs dropping to 30% after 48
- LTM may last up to a lifetime for some material
what is one strength of Baddeley (1966)?
- identified a clear difference between two memory stores
- later research showed some exceptions to Baddeley findings
- but idea STM uses mostly acoustic coding + LTM mostly semantic has stood test of time
- important step in understanding of memory system leading to MSM
what is one limitation of Baddeley (1966)?
- used quite artificial stimuli rather than meaningful material
- words no personal meaning to ptps - findings may not tell about coding when use memory in everyday life
- suggests findings in study have limited application
what is one strength of jacobs’ (1887) study?
- it has been replicated
- study is old + research in psych often lacked adequate controls
- despite this findings have been confirmed by other better controlled studies
- suggests jacobs’ study is a valid test of digit span in STM
what is one limitation of Miller’s research (1956)?
- he may have overestimated STM capacity
- Cowan (2001) reviewed other research + concluded capacity only about 4 chunks
- suggests lower end of millers estimate (5 items) more appropriate than seven items
what is one limitation of P&P (1959)?
- stimulus material artificial
- recalling consonant syllables does not reflect most everyday memory activities where what we remember more meaningful
- means study lacked external validity
what is one strength of Bahrick et al’s study (1975)?
- high external validity
- researchers investigated meaningful memories
- suggests Bahrick et al’s findings reflect a more ‘real’ estimate of duration of LTM
what is episodic memory?
- a LTM store for personal events
- are time stamped
- includes memories of when the events occured and of the people, objects, places and behaviours involved
- memories from store have to be retrieved consciously and with effort
what is semantic memory?
- not time-stamped
- a LTM store for our knowledge of the world - includes facts + our knowledge of what words & concepts mean
- usually also need to be recalled deliberately
what is procedural memory?
- a LTM store for our knowledge of how to do things
- includes our memories of learned skills
- usually recall these memories without making a conscious or deliberate effort
who is tulving (1985)? what did he propose?
- cognitive psychologist - realised MSM’s view of the LTM too simplistic + inflexible
- proposed 3 LTM stores containing different types of information:
- episodic
- semantic
- procedural
how does Tulving et al (1994) show there are different types of LTM? (ev)
- evidence from Tulving et al (1994) using PET scans- getting ptps perform tasks whilst scanned
- episodic and semantic memories tend to be recalled from prefrontal cortex (right and left)
- procedural memories tend to be recalled from cerebellum + basal ganglia
why is use of PET scan a strength?
- photographic evidence - cannot be questioned or argued with
- objective scientific evidence - high validity
what is one strength of types of LTM? ev real-life help
- able to identify diff aspects of LTM allows psychologist to target certain kids of memory problems - better lives
- ex Belleville (2006) - demonstrated episodic memories could be improved in older people with mild cognitive impairment - trained ptps performed better on test of episodic after training than control group
- shows distinguishing types of LTM - specific treatments developed
what is another strength of types of LTM? (HM + wearing) ev
evidence - wearing + HM - episodic memory impaired consequence to amnesia - difficulty recalling past events but semantic memory intact (knew concepts) also procedural (knew how to walk + speak)
- support tulving’s view there are different memory stores in LTM - one can be damaged but others unaffected
what is a counterpoint to the clinical evidence of types of LTM from HM + clive? ev
- clinical studies lack control variables
- lack of control limits what clinical studies can tell us about different types of LTM
how are cohen + squire a limitation to tulvings approach?
- limitation of Tulving’s approach - may only be 2 types of LTM
- cohen + squire (1980) - argued episodic & semantic memories stored together in one LTM store called declarative memory - but agree procedural separate (non-dec)
- therefore - possibility there are no more than two LTM stores