L4: The working memory model.

• Baddeley and Hitch (1974) came up with the working memory model. It explains how short-term memory is organised and how it is functioned.
• The four main components of the working memory model are:

  1. Central executive
  2. Phonological loop
  3. Visuo-spatial sketchpad
  4. Episodic buffer (added by Baddeley in 2000)
• Central executive

  • attentional process -> monitors incoming data
  • controls the slave systems in the WMM
  • limited processing capacity.
• Phonological loop - first slave system.

  • deals with auditory info (acoustic coding) - preserves order

  Subdivided into:

  • phonological store: stores words you hear
  • articulatory process: allows maintenance rehearsal (repeating words to keep them in working memory when needed)

  capacity of loop - two seconds' worth of what you can say.
• visuo-spatial sketchpad (second slave system)

  • stores visual and/or spatial info
  • limited capacity; three or four objects (Baddeley 2003)

  Logie (1995) subdivided the VSS into:

  1. visual cache (stores visual data)
  2. inner scribe (records arrangement of objects in spatial field)
• Episodic buffer (final slave system added by Baddeley in 2000)

  • temporary store for information - integrates verbal, visual and spatial info from other stores.
  • maintains a sense of time sequencing - recording events.
  • storage component of CE and has limited capacity of four chunks (Baddeley 2012)

  The episodic buffer links working memory to LTM and other cognitive processes (e.g., perception)
• One strength of the WMM is that it has clinical evidence to support it.

  • evidence: Shallice and Warrington's study of KF. KF had poor STM ability for verbal info BUT could process visual info normally. Suggests only his phonological loop had been damaged.
  • explain: strength as it supports the WMM's view of a separate visual and acoustic store. HOWEVER this evidence may not be reliable as it concerns a unique case.
  • link: strength - clinical evidence b/c high validity BUT low reliability.
• Another strength of the WMM is that studies into dual-task performance support the existence of the visuo-spatial sketchpad.

  • evidence: Baddeley et al. (1975) showed ppts. had more difficulty doing two visual tasks than doing a visual and verbal task at the same time. More difficult b/c both tasks compete for the same slave system.
  • explain: strength b/c it suggests there must be separate slave systems for different tasks (VSS for visual; PL for verbal).
  • link: strength - studies into dual-task performance b/c high validity.
• One weakness of the WMM is that there is a lack of clarity over the central executive.

  • evidence: cognitive psychologists suggest this component is unsatisfactory and doesn't explain much. Baddeley recognised this: "The central executive is the most important but least understood component of working memory."
  • explain: weakness because it suggests the WMM hasn't been fully explained. The central executive needs to be more clearly specified than just "attention".
  • link: weakness - lack of clarity b/c it means the WMM hasn't been fully explained.