Describe and evaluate one alternative to the multistore model of memory

   The working memory model appears to have a number of advantages over the simplistic formulation of the Atkinson and Shiffrin concept of STI\A. It effectively accounts for our ability to store information briefly, while, at the same time, actively processing the material. There is a considerable body of empirical research which seems to support the existence of the two slave systems. For example, Baddeley et al. (1975) conducted a series of studies which investigated the word-length effect. They found that memory span for visually presented one syllable words was significantly greater than for polysyllabic words. This suggests that the phonological loop is only able to hold a limited number of syllables. However, subsequent studies demonstrated that articulation time, rather than number of syllables, was the limiting factor. They compared span performance on two-syllable words such as 'cricket' and 'bishop', which are spoken quickly, with performance on two-syllable words such as 'harpoon' and 'Friday', which take longer to say. Recall was consistently better for the words which can be articulated more quickly. If participants are prevented from rehearsing the words subvocally by having to repeat an irrelevant sound such as la-la-la...' (articulatory suppression), the word-length effect disappears. It is assumed that the articulatory suppression task fills the phonological loop and, therefore, takes away the advantage of rehearsal. Based on the results of these studies, Baddeley and colleagues concluded that memory span is dependent on time rather than the number of items and that people can remember as much as they are able to say in approximately 1.5 seconds. The visuo-spatial store has not been investigated in the same depth as the phonological store, but there is experimental evidence which supports its existence. For example, Baddeley et al. (1973) gave participants a simple tracking task which involved holding a pointer in contact with a moving spot of light. At the same time, participants were asked to perform an imagery task. Participants were required to imagine the block capital letter 'F' and then, starting at the bottom left hand corner, were to classify each angle as a 'yes' if it included the bottom or top line of the letter and as a 'no' if it did not. Participants found it very difficult to track the spot of light and accurately classify the angles in the letter imagery task. However, they were perfectly capable of carrying out the tracking task in conjunction with a verbal task. This suggests that the tracking and letter imagery tasks were competing for the limited resources of the visuo-spatial scratchpad, whereas the tracking task and the verbal task were making use of the separate components of the visuo-spatial scratchpad and the phonological loop respectively. This model has proved influential and is still being developed and expanded. The main weakness, however, is that the component we know least about (the central executive) is the most important. It has a limited capacity, but no one has been able to quantify it experimentally. Richardson (1984) argues that there are problems in specifying the precise functioning of the central executive. He believes that the terminology is vague and can be used to explain any kind of results. In other words, it can give rise to a circular argument, i.e. if we give participants an articulatory suppression task and this affects performance, we assume the phonological loop is normally utilised in the task, but if performance is not affected, we assume the central executive is normally utilised in the task. Hence, it is difficult to falsify the model. My view is that we cannot falsify this model since the model is still being expanded and inaccurate ideas can be amended in the process, meanwhile, it can still be thought of as a basis for further investigation.