working memory model

• Baddeley and Hitch (1974)

  believed memory is not just one store but number of different stores:

  • 2 visual tasks = poorer performance but 1 visual and 1 verbal means no interruption
• • focuses on STM ONLY and believed it was not a unitary store (like MSM!!)
  • LTM as a more passive store that holds previously learned material for use by the STM when needed
• central executive


  • limited capacity - data arrives from the senses but it cant hold it for long
  • determines how resources (slave systems) are allocated
  • it involves reasoning and decision making tasks
• 1st slave system - phonological loop

  • limited capacity
  • deals with auditory information and preserve word order - inner ear
  • baddeley (1986) further subdivided it into:

  1. phonological store (holds words heard)
  2. articulatory process (holds words heard/seen and silently repeated looped) like an inner voice. this is a kind of maintenance rehearsal
• 2nd slave system - visuo-spatial sketch pad


  • visual and/or spatial information stored here - inner eye

  1. visual = what things look like
  2. spatial = relationships between things

  • limited capacity = 3-4 objects
  • Logie (1995) suggested subdivision:

  1. visuo-cache (store)
  2. inner scribe for spatial relations
• 3rd slave system - episodic buffer

  • baddeley (2000) added episodic buffer as he realised the model needed a more general store
  • slave systems deal with specific types of information
  • central executive has no storage capacity
  • buffer extra storage system but with limited capacity of 4 chunks
  • integrates information from all other areas
• Baddeley and Hitch (1976)

  gave participants two tasks to perform simultaneously

  task 1: true or false task occupied the central executive as it tested verbal reasoning. they were asked to perform this task at the same time as performing either...

  • asked to say 'the the the' - a task involving the articulatory loop
  • asked to say random digits - a task involving both the central executive and articulatory loop
• baddeley and hitch - results

  the true or false was slower when given the 2nd task involving both the central executive and articulatory loop
• b&h - what does the results show?

  demonstrates the dual task performance effect and shows that the central executive is one of the components of working memory

  2nd task was slower because of performing two verbal tasks at the same time. proves that the phonological loop and the sketchpad are separate systems within working memory
• b&h - does this support or challenge the working memory model?

  study of KF - short-term forgetting of auditory information was much greater than visual stimuli - brain damage was restricted to the phonological loop.

  another, LH performed better on spatial tasks than those with visual imagery. supports idea of separate visual and spatial systems as suggested by WMM.

  however studies on brain injury, one's injury is traumatic which could result a change in behaviour so that person performs poorer on certain tasks. studies are done on unique individual and cant be generalised to the population