Working Memory Model

Working Memory Model​​

Working memory model was proposed by Baddeley and Hitch in 1974. This model is an explanation of short-term memory only. This model answers some of the criticisms of the multi-store model as the multi-store model does not take into account how short term memory functions and is organised.

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Central Executive

The central executive plays a supervisory role as it monitors all the information that comes into the memory. It is considered to be an attentional system as it allocates the incoming information to the different subsystems to process. The central executive has a very limited processing capacity and does not store information.

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Phonological loop

One of the sub systems of the working memory model is the phonological loop this component deals with auditory information i.e. acoustic. The phonological loop is divided into two parts.

·      The phonological store which stores the words that you hear.

·      The articulatory process which is for maintenance rehearsal. We repeat sounds or words to keep them in our working memory whilst they are needed. It is thought that the capacity of this loop is around two seconds worth of information that you can say.

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Visual spatial sketchpad

This component deals with visual and spatial information. For example, if you had work out how many windows there are in your house you would have to visualise it. It is thought to contain around three or four objects.

·      The visual cache stores visual data

·      The inner scribe records the spatial arrangement of the objects in the visual field

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Episodic buffer

The final component of the working memory model is the episodic buffer which was added to the original working memory model in 2000. The episodic buffer is considered to be a temporary store which helps to integrate the information from the visual spatial sketchpad and the phonological loop, and helps to give information a sense of time sequencing. It is thought to be the storage component of the central executive and has a very limited capacity of around four chunks. The buffer helps to link the working memory to the long-term memory.

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Evaluation

​1. One strength of the working memory model is that it has research support from Shallice and Warrington’s 1970 case study of the patient KF. KF was a patient who had a brain injury due to a motorcycle accident. It was found that after his brain injury KF had a very poor short-term memory for auditory, sound based information but could process visual information normally. This suggests that his phonological loop was damaged, but his visual spatial sketchpad was still intact. This gives evidence for the existence of separate visual and auditory stores in short term memory.​

 

2. Another strength comes from research conducted by Baddeley in 1975, where participants were given two tasks to do at once – referred to as dual task performance. Baddeley found that when both the tasks were visual, performance was impaired because both of the visual tasks compete for the same subsystem, the visual spatial sketchpad. However, when the two tasks were different, i.e. one was a visual task and one was a verbal task, then participants had no problem completing both tasks.

 

3. A problem with the working memory is to do with the nature of the central executive. Baddeley has been criticized because he fails to elaborate on the nature of the central executive. Even Baddeley himself recognised this limitation when he said “the central executive is the most important but the least understood component of the working memory”. Therefore the central executives function needs to be clarified. Rather than referring to it as being ‘attention’ some researchers have suggested that even the central executive might contain separate subcomponents.

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