Load Theory of Selective Attention and Cognitive Control

A load theory of attention in which distractor rejection depends on the level and type of load involved in current processing was tested. A series of experiments demonstrates that whereas high perceptual load reduces distractor interference, working memory load or dual-task coordination load increases distractor interference. These findings suggest 2 selective attention mechanisms: a perceptual selection mechanism serving to reduce distractor perception in situations of high perceptual load that exhaust perceptual capacity in processing relevant stimuli and a cognitive control mechanism that reduces interference from perceived distractors as long as cognitive control functions are available to maintain current priorities (low cognitive load). This theory resolves the long-standing early versus late selection debate and clarifies the role of cognitive control in selective attention. Goal-directed behavior requires focusing attention on goal-relevant stimuli while ignoring irrelevant distractors. However, the mechanisms for such behavioral control by selective attention remain to be elucidated. In this article, we present a load theory of attention that proposes two mechanisms of selective attention. The first is a perceptual selection mechanism that allows for excludin