ABSTRACT
In the 1880s Joseph Jacobs, a London schoolmaster with an interest in the new science of psychology wanted to have a measure of the individual differences among the mental capacities of his pupils. He devised a test in which the subject was presented with a string of numbers, and attempted to repeat them back verbatim. If correct, the string was increased to a point at which errors began to occur; the subject’s digit span. The digit span paradigm has continued to be important, both practically, as it forms a subtest of the WAIS. probably the most widely used measure of adult intelligence (Wechsler, 1955), and theoretically, where the technique continues to play an important role in contemporary theorising about short-term or working memory (Baddeley. 1986). The term working memory refers to the system or systems involved in the temporary storage of information in the performance of such cognitive skills as reasoning, learning, and comprehension. It has evolved from the earlier concept of short-term memory, and can probably best be understood in the context of its development over the last 30–40 years. Before going on to examine this however, it is important to point out that the term “working memory” is also used in other ways. These will be described briefly before we consider the early development of the concepts of short-term and working memory.
