Brain Regions association with working memory

The working memory, as seen in Baddeley's model, is divided into several components. Each is associated with a different region of the brain.

Phonological Loop

• The phonological store is located in the parietal lobe
• The Articulatory rehearsal component is in both the frontal lobe and the cerebellum
• The speech production area associated with articulatory rehearsal is also known as Broca's area

Visuospatial Sketchpad

• This involves the dorsal and ventral streams
• The visual cache - storage takes place in the occipital and visual cortex
• The inner scribe - spatial rehearsal takes place in the inferior parietal lobe.

Central Executive

• The prefrontal cortex is associated with this component.
• This is the brain region that deals with higher level cognitive tasks.
• Evidence has found activation particularly in the dorsolateral region of the prefrontal cortex.

Episodic buffer

• There is little information available about the anatomical location of the episodic buffer.
• Similarly to the other three components, it is likely to be associated with multiple locations

The Central Executive

This is the interface between the two subsystems and long term memory. It is more similar to an attentional system than a memory store, as is allocates resources to the visuospatial sketchpad and the phonological loop. Baddeley (1996) suggested that the model of attentional control proposed by Norman and Shallice (1980; 1986) could provide a good model of the central executive. The functions of the central executive, as suggested by Baddeley are listed below

• Retrieval strategies,
• timesharing in dual-task performance
• selecting attention
• temporary activation of the long term memory
• suppression of habitual, automatic responses and actions

Impairments to the central executive occur in a syndrome called 'Dysexecutive syndrome' or 'frontal lobe syndrome'. These result in effects which seem as if there is no system to allocate processing resources. Individuals with the syndrome have disturbed attention and are easily distractable, making it difficult for them to learn new tasks.

Evidence for the central executive can be seen through a test involving the random generation of digits or letters:

• The participant is required to hold 1-8 digits in their memory while generating a random sequence of digits of letters.
• Close attention is needed to prevent the repetition of digits or the production of stereotyped responses (non random)
• The results show that as the digit memory load increases, the randomness decreases and the responses become more stereotyped.
• There is an implication that during the production of novel schema (made up random digits) the dominant schema (non-random sequences) must be constantly inhibited by the SAS .