Characterizing the time course and nature of attentional disengagement effects

Visual features of fixated but irrelevant items contribute to both how long overt attention dwells at a location and to decisions regarding the location of subsequent attention shifts (Boot & Brockmole, 2010; Brockmole & Boot, 2009). Fixated but irrelevant search items that share the color of the search target delay the deployment of attention. Furthermore, eye movements are biased to distractors that share the color of the currently fixated item. We present a series of experiments that examined these effects in depth. Experiment 1 explored the time course of disengagement effects. Experiments 2 and 3 explored the generalizability of disengagement effects by testing whether they could be observed when participants searched for targets defined by form instead of color. Finally, Experiment 4 validated the disengagement paradigm as a measure of disengagement and ruled out alternative explanations for slowed saccadic reaction times. Results confirm and extend our understanding of the influence of features within the focus of attention on when and where attention will shift next.