Multi-store model

• Multi store model (MSM) was designed by Atkinson and Shiffrin to describe how information flows through the memory system. Is a linear model, flow system in one direction. Passive stores- information is held onto before being passed along or lost.

  
• Sensory register: A stimulus from the environment will pass into the sensory register with many other stimuli. This means there are separate stores in the sensory register for sound, sight and smells. Iconic store for visual info and echoic for sounds.

  • coding: modality free
  • Capacity: very large
  • Duration: less then 0.5 seconds- Sperling: tested iconic store, pps saw a grid of letters for 50ms and asked to write down, accuracy for recalling a row was high but not for whole grid. Showing iconic memory is temporarily accessible but not for long.
  • Attention is used to move info to the STM
• Short term memory: (STM)

  • Coding: Acoustic
  • Capacity: 7 +/-2 (Miller) (Jacobs digit span task), any more and forgetting occurs
  • Duration: 18-30sc (Peterson and Peterson) unless rehearsed

  Maintenance rehearsal occurs when we repeat material to ourselves over and over again to keep information in the STM, if we rehearse it long enough, (prolonged rehearsal) this information can move into LTM
• Long term memory: (LTM)

  • Coding: semantically, stored in terms of meaning (Baddeley)
  • Capacity: believed to be unlimited, Bahrick found people could recognise classmates 50 years later.
  • Duration: Permanent if rehearsed for prolonged time

  Even though information is stored in the LTM, if we want to recall it it must be transferred back to the STM by retrieval.
• HM: Supports MSM

  • HM had seizures and had an operation to remove his hypocampus bilaterally.
  • After the surgery the seizures stopped however he could not form any new long term memories
  • His short term memory was left intact.
  • This supports the idea of the LTM and STM being separate stores and localisation of function.
• A03: supporting evidence

  Many studies suggesting that the STM and LTM are qualitatively different. Coding, capacity and duration research all support that the stores are independent from eachother.

  Glanzer: 24 words read and asked pps to free recall, Recall was much stronger for words at the start of the list and the end. Words heard first are in the LTM and being recalled (primary effect) and the words at the end being in the STM and being recalled (recency effect). The words in the middle were in the STM but were displaced by other words.
• A03: Research support for more then one type of STM.

  MSM states STM and LTM are unitary stores. Patient KF had amnesia and was studied, they found that his short-term memory for digits was poor when they were read aloud to him, but was much better when he could read them himself.

  This shows there must be separate stores in the STM for visual info and auditory info so MSM is a limited explanation.

  There is also evidence to support different types of LTM:

  Episodic, semantic and procedural stores. Decreases the credibility of the explanation of them being unitary stores
• A03: there is more then one type of rehearsal.

  The MSM says maintenance rehearsal (lots of rehearsal) is what transfers information from the STM to the LTM. Craik and Watkins found maintenance rehearsal just keeps information in the STM. They say elaborative rehearsal is needed to transfer information to the LTM. Elaborative rehearsal is when you link the information to your existing knowledge or you think about what it means.

  Decreases credibility of the MSM
• A03: Research into MSM lacks real world application.

  In every day life memories are related to useful things; faces, names, places. But a lot of studies supporting the MSM do not use these materials, often using digits and letters and even words with no meaning.

  This reduces the external validity and generalisability of the research.