week 8 - models of memory - multistore model Flashcards
short term vs long term
capacity
few items in ST vs essential unlimited capacity in LT
short term vs long term
time
ST - few seconds
LT- several decades
short term vs long term
what is distinction essential to?
multistore models
(some theorists propse unitary store models where the distinction is much less clear)
multistore model
proposed by?
atkinson and shiffrin 1968
extremely influential
multistore model
diagram
sensory stores –attention–> ST store –rehersal–> LT store
multistore model
sensory store
each modality-specific and holds info very briefly
vulnerable to decay
multistore model
ST store
of very limited capacity
vulnerable to displacement
multistore model
LT store
of essentially limited capacity holding info for long periods of time
vulnerable to inference
multistore model
what does the sensory store process
initally the sensory store processes environmental stimuli
info in then briefly held here
multistore model
what happenes to the info in the Sensory store
some of the info is attended to and processed further within the ST store
multistore model
sensory store
visual store
iconic memory
- holds onto info briefly
- 100ms
multistore model
sensory store
visual store
- relies on attention?
many theorists have assumed it is pre attentive
BUT
Mack (2016) obtained findings that strongly suggests it does
- participants had to report the letters in the centre of a visual array or whether four circles presented close to the fixation point where the same colour
–> much less attention to letters
multistore model
sensory store
echoic memory
auditory equivilent of iconic memory
hold auditory information for a few seconds
multistore model
sensory store
haptic memory
touch
multistore model
sensory store
olfactory memory
smell
multistore model
sensory store
gustatory memory
taste
multistore model
sensory store
evidence on capacity and duration
sperling 1960
brief presentation (50ms) is letters in 3x4 matrix
full report: name as many letters as possible
- results in about 4 letters being named
is this capacity limit?
partial report: one of 3 tones sounded to indicate which row you start with
- the tone acts as a spatial attention cue (attention –> STM)
multistore model
sensory store
evidence on capacity and duration
two main conclusions?
1) capacity
large amounts of info held in iconic memory
2) duration
after about 250-500ms performace approached full report conditions
info in iconic memory rapidly decays (+- 0.5s)
anything left was transferred to STM before it was lost
multistore model
short term memory
function?
conscious processing of information
attention is key –> limits of what info comes under the spotlight of STM at all times
multistore model
short term memory
capacity?
has very limited capacity
miller 1956 -> digit span (letter and word also) max items ~ 7 (+1-2)
cowan 2001-> probs closer to 4
multistore model
short term memory
chunking
grouping familiar stimuli for storage as a single unit
- what you can chunck depends on knowledge from LTM / expertise uou have and ability to find patterns
chunk: meaningful unit of info
“information bottle neck”
multistore model
short term memory
duration?
has limited duration
- if not rehearsed info lost within 15-20 secs
- the longer the delay the more was forgotten (forgetting curve)
DECAY
DISPLACEMENT
multistore model
short term memory
rehearsal =
the process of repetitively verbalising or thinking about the information
multistore model
short term memory
duration
forgetting only due to time decay?
no interference plays a role
multistore model
short term memory
interference
pro active interference
eariler info interferes with later info
learn A —–INTETFERENCE—–> learn B
memory loss for B
multistore model
short term memory
interference
retroactive interference
later info interferes with earlier
learn A <—INTEFERENCE—-learn B
memory loss for A
multistore model
short term memory
interference
release for proactive interference
previous trials generate inference gradual decline in performance
when nature of stimulus changes (eg. letters to numbers) again accurate recall
multistore model
short term memory
inference vs decay
some evidence for decay of info in STM
- at short retention intervals (<3.3secs)
however interference more likely cause of forgetting
- especially at (somewhat) longer intervals
multistore model
short term memory
inference when…
when stimuli are similar
when learning large vols. of info
when learning material close together in time
when learning in the same context
(no good independent evidence for displacement)
multistore model
short term memory
criticisms
info in STM does not need to be processed consciously
eg- implicit learning
simple rehearsal does not ensure LT storage
- rehearsed info does not necessarily transfer
- info in LTM has not necessarily been rehearsed during learning
learning in STM is affected by LTM (eg chunking)
double dissociation found in patients supports STM-LTM distinction
- but some patients with severly impaired STM can still aquire LTM
multistore model
short term memory
solution for criticisms
recast STM as working memory
new model developed to address some criticisms of multistore model
- loss of info not only due to decay
- different types of working memory
—> single STM store is replaced by 4 working memory components
multistore model
long term memory
once info passed from sensory store to STM ir can be ENCODED into LTM
multistore model
long term memory
function?
organises and store information
–> different systems
1) explicit/decaritive
2) implicit / non-declaritive
multistore model
long term memory
capacity?
unlimited (?)
multistore model
long term memory
duration?
permanent (?)
multistore model - limitations
over…
over simplified
eg. assumptions that ST and LT store are unitary
multistore model - limitations
several …
LTM systems
multistore model - limitations
assumption that STM store is a …
gateway between sensory store and LTM is incorrect
implicit learning is possible
multistore model - limitations
assumption that all items in STM have …
equal staus is incorrect
multistore model - limitations
only a small fraction of info. stored in LTM was …..
rehearsed during learning
multistore model - limitations
the notion that forgetting from STM is caused by displacement ….
minimised the role of interfernce
