No attentional capture for target detection: it occurs exclusively in compound search

Abstract

It has been believed that simple visual features are detected preattentively. If this description is strictly true, one should not expect attentional capture, in which attention is driven away from the target by a salient distractor, to impair performance. Consistent with this, attentional capture is generally reported only in compound search, which requires attention to be focused on the target in order to judge the response. It has been recently reported, however, that attentional capture can be produced in detection by mixing distractor trials with no-distractor trials. In this study, in a similar setting, we measured attentional capture in terms of accuracy. If detection requires attention, attentional capture should render search less accurate; however, accuracy should not be influenced by other factors, such as a slowing down in response production. We presented brief search displays in which duration was set so that accuracy was near 0.8. Results show attentional capture in compound search, but not in detection. Therefore, attention does not enhance the registering of a simple feature in the same way that it enhances compound search performance. The present results are consistent with a proposal (Chan & Hayward, 2009, JEP:HPP) that feature detection and localization involve distinct search processes.