Working Memory Model

Working Memory Model

1. Baddeley & Hitch (1974)

   • It seems that STM is far more complex than the multi-store model assumes. Working model proposes an active, multi-component short term memory store with each sub-system having its own role to play in learning, problem solving and concentration.
   • Components
     • 1) The Central Executive
       • This is the control centre responsible for coordinating the other slave units. It is able to process information from any of the senses and appears to have a minimal storage capacity. We use the central executive when we are concentrating on a task and it is sometimes likened to ‘attention.’
     • Slave Sytems
       • 2) Articulatory (phonological) loop:
         • It holds sounds for a few moments (one to two seconds), storing the sounds temporally, i.e. sounds we hear first are stored first.
           • This is important for example when we are replaying a sentence to check its meaning or when we are rehearsing a telephone number.
             • Baddeley et al (1975) found that the loop can hold about 2 seconds worth of sounds, so it can hold more short words than it can long ones.
       • 3) Visuo-spatial scratch pad
         • This also has a limited capacity and stores visual information in its component form, e.g. as shape, colour, size etc. It also considers spatial arrangement of shapes etc.
           • Used to manipulate images in our head
       • 4) Episodic buffer (2000)
         • The central executive has no storage of its own and the other two stores hold either visual or auditory data. Baddeley realised that there needed to be a store that could hold and coordinate information from all three other stores as well as from LTM.

2. Research evidence

   • This usually takes the form of getting participants to use different components of the model and examining their performance.
     • If the same component is used to carry out two tasks simultaneously then because capacity is limited performance is impaired on both tasks. However, if participants perform two tasks together that rely on different components each task can be performed normally.
       • Baddeley (1986) got participants to complete two tasks simultaneously:
         • 1. To remember a list of numbers (a so called digit span task)
           • 2. To answer true or false to a number of problems such as BA A follows B (true or false)

3. Evaluation

   • 1) Active process:
     • It sees memory as an active process and not merely a passive store. This is in keeping with more modern views of memory that don’t see it as a ‘thing’ but a function or process.
   • 2) Rehearsal:
     • It only considers rehearsal to be important in the phonological loop. It is widely considered that the multi-store model does place too great an emphasis on rehearsal in transferring information to STM.
   • 3) PET scans (Positron Emission Tomography)
     • Shows that different parts of the brain are active when different parts of the system are in use.
       • This provides further evidence for distinct components. The central executive seems to reside in the frontal cortex and the scratch pad in the right side of the occipital lobe, known to be associated with vision.

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