The working model of memory

Question 1

Validity of the model

Answer 1

As we have seen, dual-task studies are an important source of support for the working memory model. This is because they show it is much harder to successfully perform two tasks that share a subsystem (e.g. both VSS) than it is to perform tasks that use different subsystems (e.g. VSS and PL). This shows there must be separate components of working memory that process visual and verbal information.
On the other hand, dual-task studies are laboratory-based and highly-controlled. They use artificial materials that do not reflect how we use our memories in real life (e.g. tracking the movements of a light at the same time as describing the letter ‘F’). Similar artificial tasks are used in other types of supporting studies (e.g. brain-scanning studies showing different parts of the brain being used for different tasks).
Therefore, it is far from clear that working memory operates in the ways predicted by the model in everyday real-world situations. This means the use of such studies as an important source of support challenges the validity of the working memory model.

Question 2

Clinical evidence

Answer 2

One strength is support from Tim Shallice and Elizabeth
Warrington’s (1970) case study of patient KF (see also page 49).
Aiter his brain injury, KF had poor STM ability for auditory
“sound) information but could process visual information normally.
For instance his 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.
This finding strongly supports the existence of separate visual and acoustic memory stores.

Question 3

Counterpoint clinical evidence

Answer 3

However, it is unclear whether KF had other cognitive impairments (apart from damage to his phonological loop) which might have affected his performance on memory tasks. For example, his injury was caused by a motorcycle accident. The trauma involved may have affected his cognitive performance quite apart from any brain injury.
This challenges evidence that comes from clinical studies of people with brain injuries that may have affected many different systems.

Question 4

Dual-task performance

Answer 4

Another strength is that studies of dual-task performance support the separate existence of the visuo-spatial sketchpad.
When Baddeley et al’s (1975) participants carried out a visual and verbal task at the same time (dual task), their performance on each was similar to when they carried out the tasks separately. But when both tasks were visual (or both were verbal), performance on both declined substantially. This is because 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).

Question 5

Nature of the central executive

Answer 5

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 Practical activity on page 64
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