A Multicomponent Model of Working Memory

The multicomponent model aims to provide a broad theoretical framework enabling both more detailed fractionation and analysis of its components, and a capacity for it be used fruitfully beyond the laboratory. In its current form it comprises four interacting components. Two of these are modality-specific memory storage systems, one verbal-acoustic, the phonological loop, and one visuospatial, the sketchpad. Information in both these stores can be temporarily maintained via focused attention termed ‘refreshing’, while the phonological loop can also maintain familiar verbalizable material by subvocal or overt rehearsal. Both subsystems are controlled by a third component, the central executive, a supervisory system with limited resources. The central executive is principally concerned with internally directed attentional control processes but also has a role in the attentional selection of perceptual information. Information from these three components is coordinated with information from perception and long-term memory through the fourth component, a multidimensional, multimodal episodic buffer. This component is capable of holding up to around four episodic chunks, and is a valuable but essentially passive storage system, controlled by the central executive and accessible to conscious awareness. The multicomponent model has been systematically developed using a number of experimental tools. These include, principally, similarity effects to identify the type of coding involved, concurrent task methods to assess the contributions of the various subsystems to complex tasks, and neuropsychological evidence, in particular from the study of single cases with very specific deficits. The model continues to evolve and has proved successful both in accounting for a broad range of data on memory and related cognitive areas and in its application to the understanding of a wide range of cognitive activities and populations.