Publications

Abstract

Research on task switching and dual-task performance has spawned two literatures that have, to a surprising extent, developed independently. This tutorial reviews the principal findings of each tradition and considers how these phenomena may be related. Beginning with Jersild 1927, task-switching studies reveal that when people perform two tasks in succession, with each task requiring different responses to the same set of stimuli, substantial slowing occurs. Recent research suggests that while this slowing can be partially ameliorated by allowing sufficient time between tasks, advance reconfiguration is almost always incomplete. In studies of dual-task performance, stimuli arc presented very close together in time, and subjects attempt concurrently to perform two wholly distinct tasks. A substantial slowing of one or both tasks is usually observed. The most stubborn source of this slowing appears to be queuing of central processing stages, sometimes supplemented by other kinds of interference. This queuing occurs even when the tasks are highly dissimilar and is unlikely to reflect voluntary strategies. A number of possibilities for how task switching and dual-task queuing plight be related are discussed critically, including the possibility that queuing might stem from an inability to maintain two distinct task sets at the same time.