working memory model

• Baddeley and Hitch

  • Proposed the WMM as an alternative to the STM
  • Arguing that the STM is more complex
  • The WMM is concerned with the ‘mental space’ that is active when, for example, working on an arithmetic problem or playing chess or comprehending language
• central executive (CE)

  • Supervisory role:
  • Monitors incoming data
  • Directs attention
  • Allocates subsystems to tasks
  • Coding = flexible
  • Capacity = very limited
• phonological loop (PL)

  • Deals with auditory information
  • Preserves the order in which the information arrives
  • Subdivided into:
  • Phonological store = stores the words you hear (inner ear)
  • Articulatory process = allows maintenance rehearsal (repeating sounds to keep them in WM while they are needed) (inner voice)
  • Coding = acoustic
  • Capacity = about 2 seconds
• Visio-spatial sketchpad (VSS)

  • Stores visual and/or spatial information when required
  • (Eg = recalling how many windows your house has)
  • Logie subdivided the VSS into:
  • Visual cache = stores visual data
  • Inner scribe = records arrangement of objects in visual field
  • Coding = visual and spatial
  • Capacity = 3 or 4 objects (limited)
• Episodic buffer (EB)

  • Added by Baddeley later
  • Temporary store for information
  • Integrates visual, spatial and verbal information from other stores
  • Maintains sense of time sequencing = recording events (episodes) that are happening
  • Links to the LTM
  • Coding = flexible
  • Capacity = about 4 chunks (limited)
• strength = support from clinical evidence

  • Eg = Shallice and Warrington = studied patient KF who had a brain injury
  • His STM for auditory information was poor (damaged PL) but he could process visual information normally (intact VSS)
  • Supports the WMM view that there are separate visual and acoustic memory stores
• counterpoint to support from clinical evidence

  • KF may have had other impairments which explained poor memory performance, apart from damage to his PL
  • This challenges evidence from clinical studies of brain injury
• strength = dual task performance studies support the VSS

  • Baddeley et al = his participants found it harder to carry out 2 visual tasks at the same time than do a verbal and visual task together (same for 2 verbal tasks)
  • This is because both visual tasks compete for the same subsystem (VSS) - there is no competition with a verbal and visual task
  • => there must be a separate subsystem that processes visual input (VSS) and also a separate system for verbal processes (PL)
• limitation = lack of clarity over the central executive

  • Baddeley = said the CE was the most important but the least understood component of working memory
  • There may be more to the CE than just ‘attention‘ (eg it is made up of separate subcomponents)
  • => the CE is an unsatisfactory component and this challenges the integrity of the model
• extra evaluation = validity of the model

  • dual-task studies support the WMM = because they show that there must be separate components processing visual (VSS) and verbal information (PL)
  • BUT these studies are highly-controlled and use tasks that are unlike everyday working memory tasks (eg recalling random sequences of letters)
  • This challenges the validity of the model because it is not certain that working memory operates this way in everyday situations