Working Memory Model

• Baddeley and Hitch (1974) felt that STM wasn’t just one store, but a number of different stores because research seemed to indicate that if you do two things at the same time and they’re both visual tasks, you perform them less well but if you do two tasks at the same time and one is a visual task whereas the other involves sound then there appears to be no reduction to your ability. This seems to suggest that the STM must contain separate visual and sound stores
• The central executive directs attention to particular tasks. It controls the other systems by determining how resources will be allocated. The CE has limited capacity so it can’t attend to many things at the same time
• The phonological loop controls auditory information. Further subdivided into the phonological store which holds the words you hear and the articulatory process which rehearses words you have seen
• The visuo-spatial sketchpad processes visual and spatial information. The visual cache stores information about items such as colour and form and the inner scribe stores the arrangement of objects
• The episodic buffer is a general store that maintains a sense of time sequence- basically recording events that are happening and sending information to the LTM
• Shallice and Warrington (1970) studied a man called KF whose short-term forgetting of auditory information was much greater than that of visual stimuli. in addition his auditory problems were limited to verbal material like letters and digits but not meaningful sounds. thus his brain damage seemed to be restricted to the phonological loop. this supports the idea of separate visual and spatial systems, as suggested by the WMM
• the main reason for developing the WMM was to account for dual task performance, described on the facing page. Hitch and Baddeley (1976) supported the existence of the central executive in a study which demonstrated that the dual task performance effect and shows that the central executive is one of the component of working memory
• there are a number of problems with using evidence from case studies of individuals who have suffered serious brain damage. the process of brain injury is traumatic, which may in itself change behaviour so that a person performs worse on certain tasks. such individuals may have other difficulties like difficulties paying attention and therefore underperform on certain tasks. this is an issue for the WMM as some of the key research that supports the WMM comes from case studies