working memory model - evaluation

Question 1

The case of KF supports separate STM stores

Answer 1

• Shallice and Warrington (1970) carried out a case study of patient KF who had brain damage
• He had poor STM ability for verbal information but could process visual information normally
• So, his phonological loop had been damaged but other areas of memory were intact
• This suggests there are separate visual and acoustic stores

Question 2

It explains results of dual-task studies

Answer 2

• Baddeley et al (1975) found Ps had more difficulty doing two visual tasks than doing a visual and verbal task at the same time
• The greater difficulty is because both visual tasks compete for the same limited resources, whereas there is no competition in doing a verbal and visual task simultaneously
• This provides existence for the visuo-spatial sketchpad

Question 3

The word length effect supports the phonological loop

Answer 3

• Baddeley et al (1975) found people have more difficulty
  remembering long words than short words
• This shows that the capacity of the phonological loop is the time it takes to rehearse (approximately 2 seconds) = this is the word length effect

Question 4

It is supported by brain studies - central executive

Answer 4

• Braver et al’s (1997) Ps did tasks involving the CE while they were having brain scan
• Activity seen in the prefrontal cortex increased as the task became harder
• This makes sense in terms of the WMM: as demands on the CE increase, it has to work harder to fulfil its function

Question 5

There is a lack of clarity over the central executive

Answer 5

• Cognitive psychologists suggest that the CE is unsatisfactory and doesn’t really explain anything
• The CE should be more clearly specified than just simply ‘attention’

Question 6

Psychologists have criticised the visuospatial sketchpad

Answer 6

• Lieberman (1980) said that the VSS implies that all spatial information was first visual
• However, Lieberman points out that blind people have excellent spatial awareness, although they have never had any visual information
• Lieberman argues that the VSS should be separated into two different components: one for visual information and one for spatial