4. WMM

• What is the working memory model?

  • An explanation of how STM is organised and how it functions
  • Concerned with the 'mental space' that is active when we are temporarily storing and manipulating information
  • The model consists of four main components, each of which is qualitatively different especially in terms of coding and capacity
• Central executive

  • 'Supervisory' role
  • Monitors incoming data, focuses and divides our limited attention and allocates subsystems to tasks
  • Limited processing capacity and does not store information
  • Codes depending on the sense
• Phonological loop

  • Deals with auditory information and codes acoustically
  • Preserves the order in which information arrives
  • Limited capacity of 2 seconds
  • Subdivided into a phonological store (stores the words you hear) and articulatory process (allows maintenance rehearsal and a 2 second capacity worth of what you can say)
• Visuo-spatial sketchpad

  • Stores iconic memory when required
  • Has a limited capacity of 3-4 items
  • Codes iconically
  • Subdivided into visual cache (stores visual data) and inner scribe (records the arrangement of objects in the visual field)
• Episodic buffer

  • Temporary store for info integrating the visual, spatial and verbal info processed by other stores and maintaining a sense of time-sequencing recorded events
  • Can be seen as the storage component of the CE
  • Codes depending on the sense
  • Limited capacity of 4 items
  • Links working memory to LTM and perception
• Strength - case studies/clinical evidence

  • Shallice and Warrington study of patient KF
  • After his brain injury, KF had poor STM ability for auditory information but could process visual information normally
  • Phonological loop was damaged but his visuo-spatial sketchpad remained intact
  • Supports the idea of separate subsystems within the WMM
• Counterpoint - did KF have other cognitive impairments?

  • If there is, they might have affected his performance on memory tasks
  • His injury was caused by a motorcycle accident and the trauma involved may have affected his cognitive performance
• Strength - studies of dual task performance

  • Supports separate existence of the VSS
  • When Baddely's pps carried out a visual and verbal task at the same time their performance on each was similar to when carried out separetely
  • When both tasks were visual or both verbal, performance on both declined substantially due to both tasks competing for the same subsystem
  • Shows support for seperate subsytems
• Limitation - lack of clarity over the nature of the CE

  • Baddely recognised this himself when he said 'The central executive is the most important but least understood component of working memory'
  • It needs to be more clearly specified than just simply being 'attention' - some psychologists believe the CE may consist of separate subcomponents
  • Challenges integrity of WMM