2. multi-store model of memory

what is the MSM

• a representation of how memory works in terms of three stores called the sensory register, STM and LTM

• describes how information is transferred from one store to another, what makes some memories last and what makes some memories disappear

atkinson & shiffrin

MSM diagram

in simple forms what does the MSM suggest

it suggests that memory is made up of three stores linked by processing

the sensory register

• all stimuli from our environment pass into the sensory register, and there are several registers with one for each of our senses

coding, capacity and duration of the sensory register

• CODING - it is modality specific (ie depends on the sense) in each store. the store coding for visual info is iconic memory, and the store coding acoustically is echoic memory

• DURATION - very brief (less than half a second)

• CAPACITY - very high for example there are over one hundred million cells in one eye, each storing data

whys the duration short

• because the brain recieves millions of pieces of information from the SR every second

• it would be impossible for it to retain or give attention to this amount of data, nor does it need to

key process connecting the SR to STM

attention

• if its paid to the information passing into the SR then it can be passed on to STM

STM

• CODING - mainly acoustically

• DURATION - lasts about 18s unless it is rehearsed so it is more of a temporary store

• CAPACITY - limited, between 5 and 9 items of info though cowan’s research suggests it may be more like 5 rather than 9

maintenance rehearsal

• it occurs when we repeat (rehearse) material to ourselves over and over again - we can keep info in our STM as long as we rehearse it

• if we rehearse it long enough it passes into LTM

elaborative rehearsal

involves deeper processing ie learning lines for a play

LTM

• CODING - mainly semantically

• DURATION - up to a lifetime

• CAPACITY - practically unlimited

according to the MSM, when we want to recall info from LTM, it has to be transferred back into STM by a process called retrieval

evaluation

1. case study support

2. research support (& counterpoint)

3. more than one STM store

4. bygone model

case study support

• HM has his hippocampus removed

• following his surgery he could remember events and some information from before the surgery (LTM) but he could not form new memories (STM could not be transferred to LTM)

• adds weight to argument that the brain uses separate regions or structures for STM and LTM

research support

• evidence supports idea that STM and LTM are separate stores

• baddeley found that we mix up similar sounding words in STM but mix up words with similar meanings in LTM - suggests they use different coding systems, supporting the MSM

• confirms the MSM claim that they are independent memory stores

• controlled lab study so internal validity

counterpoint

• research used artificial materials not reflective of real life memory use, lack ecological validity

• studies used digits, word lists and meaningless consonant syllables rather than meaningful memories like names or faces

• makes MSM less valid as a model of everyday memory, suggesting it may not accurately represent real world memory processes

more than one STM store

• the MSM assumes STM is a single unit, but research suggests otherwise

• shallice & warrington studied a client referred to as KF who had a clinical memory disorder called amnesia. found he has poor STM for verbal info but a normal STM for digits

• indicates there are different STM stores for auditory and visual info, contradicting the MSM claim that it is a single, undivided store

bygone model

• MSM is based on outdated research that does not fully explain modern memory understanding

• research now suggests LTM is made up of different types (episodic, semantic, procedural) and is not just one unitary store

• MSM is reductionist as fails to account for these distinctions, raising question of whether it is still a useful model of memory today