2.2 the multi-store model of memory 💚

Key terms

Multi-store model — a representation of how memory works in terms of 3 stores: sensory register, STM, LTM

Sensory register — the memory stores for our senses. Coding for iconic is visual and the echoic is acoustic. The capacity is very large (millions of receptors), short duration (less than half a second)

Proposed by Richard Atkinson and Richard Shiffrin

Sensory register

  • where all stimuli from the environment passes into

  • Coding is modality specific. Duration is very brief, less than half a second. Capacity is very high

  • Information passes into STM if you pay attention

Short term memory

  • coded acoustically, duration of around 18 seconds, limited capacity (7 +-2)

  • Information is kept in the STM is we rehearse it, maintenance rehearsal (repeating material over and over)

  • Maintenance rehearsal leads to prolonged rehearsal which allows info to enter the LTM

Long term memory

  • coded semantically, duration lasts up to a lifetime, capacity is potentially unlimited

  • When we want to recall info from the LTM, it is transferred back into the STM by retrieval

Case study of HM

  • underwent brain surgery to relieve his epilepsy in which his hippocampus was removed from both sides of his brain. He could not form new long-term memories. However he performed well on STM tests

Evaluation

Research support

  • Baddeley showed that STM and LTM are different, independent memory stores as they code information differently

  • Counterpoint — however Baddeley research may not have been valid because the semantic words had no personal meanings

More than one STM store

  • Shallice and Warrington studied KF, a client who had amnesia. He struggled to recall digits when they were read out loud, and his recall improved when he read the digits himself.

  • Shows there might be another STM store for non-verbal sounds

  • So the MSM is wrong in claiming there is just one STM store

Elaborative rehearsal

  • prolonged rehearsal is not needed for transfer to LTM. Craig and Watkins found that the type of rehearsal is more important than the amount.

  • E.g Elaborative rehearsal can be used, when you link info to your existing knowledge

More than one store for LTM

  • Tulving found that there are 3 stores for LTM: episodic, semantic and procedural

  • Shows the MSM is an oversimplified model of memory