The Functional Organization and Capacity Limits of Working Memory

Working memory refers to keeping track of ongoing mental processes and temporary memory. One hypothesis is that this form of memory consists of multiple domain-specific components. Over four decades, experiments testing this hypothesis have yielded insight into cognitive changes from childhood to old age, selective cognitive impairments following brain damage, and on-line cognition in healthy adults. Advances in the understanding of working memory also have arisen from the discovery of associations between individual differences in working-memory capacity and a broad range of cognitive measures. These latter advances have often been interpreted as supporting the alternative hypothesis that working memory consists of a single, limited-capacity domain-general system for control of attention. Here I outline recent developments in the multiple-component perspective that address challenges derived from the attention-based hypothesis and from multivariate studies of individual differences. I argue that the multiple-component perspective and the single-attentional-system perspective are complementary, with each best suited to asking different research questions, and that many areas of contemporary debate regarding the nature of working memory reflect differences that are more apparent than real.