Multi-store model of memory

Who designed the multi-store model of memory?

Richard Atkinson & Richard Shiffrin

Define the multi-store model of memory

• A representation of how memory works in terms of sensory register, short-term memory & long-term memory. Describes how information is transferred from one store to another, what makes some memory last & disappear

Describe the first stage

• All stimuli from environment e.g someone talking, pass into sensory register - comprises several registers, one for each of 5 senses

• Coding is modality specific (depends on sense) - e.g store coding visual info is iconic memory & store coding auditory info is echoic memory

• Duration 0.05 seconds for iconic memory but about 3 seconds for echoic memory

• Very high capacity

• Information passes further into memory system only if you pay attention

Describe the second stage

• Short term memory lasts about 18 seconds unless rehearsed

• Coded acoustically

• Temporary & limited capacity - about 5-9 items

• Maintenance rehearsal occurs when we repeat information to ourselves repeatedly until enters LTM

Describe the third stage

• LTM potentially lasts up to a lifetime & potentially unlimited capacity - info coded mostly semantically

• When we want to recall info from LTM, it has to be transferred back into STM through retrieval.

Evaluation - separate stores & counterpoint

• Larry Squire reviewing neuroimaging studies that compared brain areas associated with STM & LTM

• Prefrontal cortex significantly active during tasks involving STM whereas hippocampus (+ other structures) have been associated with reorganisation & consolidation (LTM)

• Regional differences suggest LTM & STM are independent & separate stores

→ Counterpoint: others argue this view is oversimplified & there is significant overlap & interaction between brain regions that support STM & LTM e.g hippocampus also involved in STM tasks, particularly when task involves complex & new info. This suggests that evidence for a clear-cut separation is not strong

Evaluation - elaborative rehearsal

• Fergus Craik & Michael Watkins found that type of rehearsal is more important than amount

• Elaborative rehearsal is needed for long-term storage - occurs when you link information to existing knowledge, meaning info can be transferred to LTM without maintenance rehearsal

• This suggests that MSM does not fully explain how LTM storage is achieved

Evaluate - clinical evidence + Counterpoint

• Limitation – Shallice & Warrington (1970): Studied KF, who suffered brain damage after a motorcycle accident.

• KF had poor acoustic STM, but his visual STM was normal.

• This suggests his phonological loop was damaged, but his visuospatial sketchpad was unaffected, supporting the existence of separate STM stores.

Counterpoint:

• KF may have had other cognitive problems that affected his memory performance.

• The trauma from his accident may have affected his performance, rather than just the brain damage.