Evidence is presented that supports the view that most models of short-term memory cannot account for the flexibility of the primary memory system. It is argued that the working memory model outlined by Baddeley and Hitch (1974) is, however, a potentially adequate model. Working memory, in this thesis, is depicted as a system that assembles 'constellations' consisting of the central executive and one or more sub-systems. This view suggests a formulation that is considerably more complex than the 1974 model. The empirical studies examine the role of the visuo-spatial scratch pad in the formation and maintenance of working memory constellations. It is concluded from these studies that the scratch pad is independent of the articulatory loop but is usually coupled to the central executive except during maintenance rehearsal. Furthermore, it can be used concurrently with the articulatory loop to process spatial aspects of highly verbal tasks. However a constellation consisting of the executive, the loop and the scratch pad is vulnerable to a wider range of interference effects than a simpler constellation. Paivio (1971) suggested that 'dual coding' leads to better memory performance, however, this is only the case when no distractors are present. The final two chapters present some speculations on how working memory research might proceed in the future. It is concluded that the current trend towards collecting convergent evidence and the emphasis on testing theory in applied situations should give us insights into memory that were not available to Ebbinghaus and other early memory researchers.

<p>This study examined the idea that each mathematical operation (addition, subtraction, multiplication and division) is mainly linked to one of the components of working memory as proposed by Baddeley. The phonological loop, visual-spatial sketchpad and central executive have been studied using a dual-task methodology with 7 different secondary tasks. 35 undergraduate and graduate students were timed in their response time for mental calculation and error rates were calculated. Results show clear differences of operations and of number pairs. Interaction between conditions and operations was just approaching significance. Results did not give support to the idea that operations can be linked to a certain working memory component. Several factors, such as language, problem size, lack for detail in the working memory model, difficulty of the secondary tasks, and internal validity problems are discussed with regard to the results and mental arithmetic.</p>

This study examined the idea that each mathematical operation (addition, subtraction, multiplication and division) is mainly linked to one of the components of working memory as proposed by Baddeley. The phonological loop, visual-spatial sketchpad and central executive have been studied using a dual-task methodology with 7 different secondary tasks. 35 undergraduate and graduate students were timed in their response time for mental calculation and error rates were calculated. Results show clear differences of operations and of number pairs. Interaction between conditions and operations was just approaching significance. Results did not give support to the idea that operations can be linked to a certain working memory component. Several factors, such as language, problem size, lack for detail in the working memory model, difficulty of the secondary tasks, and internal validity problems are discussed with regard to the results and mental arithmetic.