Evaluation of WMM

• strengths

  • evidence for brain damaged patients (Shallice and Warrington)
  • dual task performance (Baddeley et al)
• evidence from brain damaged patients

  clinical evidence of patients with brain damage have shown support for WMM. some brain damaged patients have revealed damage in their ability to process verbal information but not visual information

  e.g. Shallice and Warrington's (1970) case study of KF. after his brain damage he had difficulty processing sounds (verbal) but he could recall digits and letters (visual)-> suggests that just his phonological loop had been damaged leaving other areas of working memory intact
• evidence from brain damaged patients COUNTER

  case studies are investigating unique individuals, often portraying extreme or rare situations. this makes it difficult to generalise to the wider population
• dual task performance

  studies of dual-task performance support the separate existence of the visuo-spatial sketchpad

  e.g. Baddeley et al. (1975)- learnt about in previous lesson
• limitations

  • problems with patients with brain injury
  • central executive is too vague
• problems with patients with brain injury

  the process of brain injury is traumatic, which may in itself change behaviour so that a person performs worse on certain tasks

  in addition, individuals may have other difficulties, such as difficulty paying attention, and that is why they underperform on certain tasks
• central executive is too vague

  critics feel the notion of a single central executive is wrong and that there are probably several components

  Eslinger and Damasio (1985) studied patient EVR who had a cerebral tumour removed. he performed well on tests requiring reasoning, which suggested that his central executive was intact. however, he had poor decision-making skills (he would spend hours trying to decide where to eat, for example), which suggests that in fact his central executive was not wholly intact