Working Memory Model AO1

• Two slave systems are independent of eachother which means it is possible to rehearse a set of digits in the articulatory-phonological loop while at the same time making decisions about the spatial layout of a set of letters in the visuo spatial sketchpad 
• However the slave systems also have a limited capacity and therefore if two tasks are performed which use the same slave system performance on one or both of these will be impaired.

• Original WMM has been extended by Baddeley to inclide an episodic buffer that intergrates and manipulates from all components of WM.
• One of its important functions is to intergrate material from LTM to meet the requirments of WM

• Baddeley & Hitch proposed that STM is made up of several different stores
• The central executive can be described as attention and controls two slave systems. All three have limited capacity
• The articulatry phonological loop deals with auditory information. it contains a phonological store and articulatory control system.
• The visuo spatial sketchpad deal with the temporary storage of visual and spatial information

Strengths 

• The model can explain how we can successfully do two tasks at the same time if the tasks involve different stores, but why we have trouble performing two tasks at the same time if they involve the same stores
• PET scans show that different areas of the brain are activated during workin memory tasks
• Real world applications-in the workplace because there is such a high correlation between WM span and performance on various tasks. It has been suggested that WM capacity might be used as a measure of suitability for certain jobs. Specifically there have been investigations into its use as a recruitment tool for the US air force
• Evidence of the spatial sketchpad-Baddeley gave pts a visual tracking task. At the same time they were given one of two other tasks, task 1-describe all the angles on the letter F, task 2- perform a verbal task. Task 1 was difficult but not task 2, presumably because the second task involved two different components.

Weaknesses

• Least is known about the precise function of the most important component, the central executive, and the suggestion that there may be a single central executive may be innacurate.
• Most of the research into WM was focused on the slave system rather than the centrail executive. The result is that central executive, which governs the whole system has relatively little experimental support. For example the central executive is said to have limited capacity but the actual capacity has not been established. Also it is not clear how it functions modality free. The way in which it functions such as allocating resources, is also not clearly understood.
• Eysenck argues that the idea of a unitary central executive could be as misguided as seeing STM as a unitary attentional system. It may be more than one system, each possibly consisting of more than one component.