working memory model

• Working Memory Model (WMM)

  A model of short-term memory proposed by Baddeley and Hitch (1974)
• The WMM is a response to the over-simplification of short-term memory in the multi-store model
• Components of the WMM

  • Central executive
  • Phonological loop
  • Visuo-spatial sketchpad/scratchpad
  • Episodic buffer
• Central executive


  • Controls the WMM
  • All information passes to it and it decides which component should process it
  • The components can only communicate with each other via the CE
  • It is modality free - can process information from any of the 5 senses
  • May be involved in highly complex tasks such as playing chess
• Phonological loop


  • Holds information in the form of speech/sound
  • Has a phonological store/inner ear which deals with speech perception and an articulatory control process/inner voice which processes speech production and rehearses verbal information
  • Easiest of the slave systems to test
• Visuo-spatial sketchpad/scratchpad


  • Concerned with visual and spatial information which it organises into separate components
  • Has an inner scribe which deals with spatial information and a visual cache which stores information about form, shape and colour
• Episodic buffer


  A temporary storage device used to integrate information from the VSS and PL
• The episodic buffer was added to the WMM in 2000
• The episodic buffer ensures that all the information from the slave systems links together and forms a cohesive whole which makes sense
• Dual-task studies


  1. Two tasks are possible at the same time if they use different slave systems e.g. the PL and the VSS

  2. Attempting two tasks using one slave system overloads that system
• The case study of brain-damaged patient KF (Shallice & Warrington, 1970) provides research support for the WMM
• Strengths of the WMM

  • It extends on the work of the MSM and explains the complexity of STM with the tasks it can perform
  • Research on dual tasks (Baddeley 1973) supports the idea of separate components and how they can be overloaded
• Limitations of the WMM

  • It is vague on the link between STM and LTM
  • It is difficult to measure the CE which means that not much is actually known about it