AO3

• Clinical evidence

  • Support from Shallice and Warrington's (1970) case study of patient KF
  • KF had poor STM ability for auditory (sound) information but could process visual information normally
  • KF's immediate recall of letters and digits was better when he read them (visual) than when they were read to him (acoustic)
  • KF's phonological loop was damaged but his visuo-spatial sketchpad was intact
• Shallice and Warrington's finding strongly supports the existence of separate visual and acoustic memory stores
• KF's injury was caused by a motorcycle accident, and the trauma involved may have caused other cognitive impairments
• This challenges evidence that comes from clinical studies of people with brain injuries that may have affected many different systems
• Dual-task performance


  • Studies of dual-task performance support the separate existence of the visuo-spatial sketchpad
• Dual task performance by Baddeley et al. (1975)


  1. Participants carry out a visual and verbal task at the same time

  2. Performance on each is similar to when they carry out the tasks separately

  3. When both tasks are visual (or both are verbal), performance on both declines substantially
• Both visual tasks compete for the same subsystem (VSS) whereas there is no competition when performing a verbal and visual task together
• This shows there must be a separate subsystem (the VSS) that processes visual input (and one for verbal processing, the PL)
• One limitation is that there is a lack of clarity over the nature of the central executive
• Baddeley (2003) himself recognised this when he said, 'The central executive is the most important but the least understood component of working memory'
• The CE needs to be more clearly specified than just being simply 'attention
• For example, some psychologists believe the CE may consist of separate subcomponents
• This means that the CE is an unsatisfactory component and this challenges the integrity of the WMM
• Studies use tasks that are very unlike the tasks we perform in our everyday lives (e.g. identifying the correct order of letters such as A and B, recalling random sequences of letters)
• Studies are also carried out in highly-controlled lab conditions (e.g. where presentation of stimuli is precisely timed)