The behaviour of “short-term memory” patients on short-term memory tasks is of interest because their performance contrasts so strongly with those of normal adults. The approach of contrasting normal adult behaviour with that of other groups can be extended to other populations whose performance differs markedly from the normal adult pattern. This part includes discussions of short-term memory performance in children (Hitch, chapter 9); in the elderly (Craik, Morris, & Gick, chapter 10); in the deaf – or rather the procedure, lipreading, they use (Campbell, chapter 11) and in two types of neurological patients (Howard & Franklin, chapter 12; Kinsbourne & Hicks, chapter 13).

Hitch (chapter 9) reports a number of studies concerning the development of working memory in children of various ages. He suggests that developmental studies may usefully complement neuropsychological research in advancing our understanding of normal cognitive processes, such as short-term memory, since both can be based on a “fractionation” methodology. The neuropsychological fractionation method currently used in patients with acquired brain lesions capitalizes on the presumed more or less complete damage of specific functional component(s), for example, the phonological short-term store, to investigate the functional architecture of aspects of the cognitive system. In the case of normal children the fractionation approach advocated by Hitch assumes that the normal development of cognitive abilities may be characterized by the addition of subsystems, which previously were relatively nonoperative. If this is the case, the study of children of different ages should produce results complementary to those obtained with brain-damaged patients.