Baddeley and Hitch (1974) developed an alternative model of short-term memory which they called the working memory model. The working memory model consists of four components. The central executive which controls and co-ordinates the operation of two subsystems, the phonological loop and the visuo-spatial sketchpad. The central executive controls attention and coordinates the actions of the other components, it can briefly store information, but has a limited capacity. The phonological loop consists of two parts, the articulatory control system and the phonological store.
The articulatory control system (the inner voice) where information is rehearsed sub vocally and has a capacity of about 2 seconds. The phonological store (the inner ear) stores information in speech-based form, the speech input is held for a brief duration. The third component, the visuo-spatial sketchpad, mentally manipulates images and space, for example it is used when a person imagines the encodes visual information in terms of separate objects as well as the arrangement of these objects in one’s visual field.
The final component, episodic buffer, receives input from many sources, temporarily stores this information, and then puts them together in order to construct a mental episode of what is being experienced right now. The evidence of the existence of the working memory model offers a better account than the STM component of the multi-store memory model. This is because it moves from describing immediate memory as a unitary store to one with a number of components.
1.1 Explain the purpose of storing and retrieving required information Storing information is a process where information is stored or kept within a store house. A storehouse includes places such as cabinets, HDD which is a hard disk drive, memory sticks or floppy disks depending on the kind of information that you are trying to store. Retrieving information is the process of regaining the ...
The working memory model does not over emphasize the importance of rehearsal for STM retention, in contrast to the multi-store model. It is an optional process rather than the only means by which information is kept in immediate memory. The working memory model also explains many psychological observations. The KF case study supports the Working Memory Model. KF suffered brain damage from a motorcycle accident that damaged his short-term memory. KF’s impairment was mainly for verbal information – his memory for visual information was largely unaffected.
This shows that there are separate STM components for visual information (visuo-spatial sketchpad) and verbal information (phonological loop).
However, there are also arguments to suggest weaknesses of the working memory model. The main limitation is the lack of evidence for the central executive, some psychologists believe it is too vague. Critics also feel that the notion of a single central executive is wrong and that there are probably several components. This could make the working memory model appear reductionist because it has only been described as being unitary and over simplified.
From this, it could be suggested that it is lacking in detail and is not fully reliable. Finally, much of the supporting evidence for this model comes from the study of brain-damaged individuals, where it is impossible to make ‘before and after’ comparisons, so it is not clear whether changes in behaviour is caused by the damage. Finally, the process of brain injury is traumatic, which may in itself change behaviour. These factors limit the validity of any conclusions drawn.