The working memory model

• Working memory model (WMM)


  An explanation of how short-term memory is organised and how it works
• WMM


  • Concerned with the part of the mind that is active when we are temporarily storing and manipulating information from the environment
• Components of WMM

  • Central executive
  • Phonological loop
  • Visuospatial sketchpad
  • Episodic buffer
• Central executive


  Described as an 'attentional process' with a very limited processing capacity, and whose role is to allocate tasks to the 3 slave systems
• Phonological loop


  • Processes auditory information and preserves the order in which the information arrives
  • Has two sub-divisions: phonological store (stores the words you hear) and articulatory process (allows for maintenance rehearsal)
• articulatory process

  • Capacity is believed to be two seconds of what you can say
• Visuospatial sketchpad


  • Combines the visual and spatial information processed by other stores, giving us a 'complete picture'
  • Capacity is limited to about 3-4 objects
• Visuospatial sketchpad sub-divisions

  • Visual cache (stores visual data)
  • Inner scribe (records the arrangement of objects in the visual field)
• Episodic buffer

  • The storage component of the central executive
  • Temporary store for information, integrating the visual, spatial and verbal information processes by the other stores and maintaining a sense of time sequencing
  • Capacity is approx. 4 chunks
  • Links working memory to long-term memory and wider cognitive processes such as perception
• Shallice and Warrington's study of KF provides support for the WMM because their findings show that KF had very poor STM recall for auditory stimuli, but increased STM recall for visual stimuli
• Studies of dual-task performance, where each participant must undertake a visual and verbal task simultaneously, shows decreased performance for such tasks and so supports the idea that the central executive has a very limited processing capacity
• Neuroscanning evidence, such as that provided by Braver et al, has demonstrated a positive correlation between an increasing cognitive load processed by the central executive (as marked by increasing task difficulty) and increasing levels of activation in the prefrontal cortex
• The WMM hasn’t been fully explained which undermines the validity of the model as a whole.


  Alan Baddeley (2003) himself recognised this when he said: ‘The central executive is the most important but least understood component of working memory’. The central executive needs to be more clearly specified than just being simply an ‘attentional process’ - some psychologists believe it may even consist of separate components.