Abstract
Highly salient distractor stimuli may prolong reaction times to a target stimulus. This distraction effect is largely due to the fact that our eyes are sometimes captured by the distractor. To respond to the target, the eyes need to be redirected from the distractor to the target which is time-consuming. Distractors that are similar to the target cause a stronger distraction effect than dissimilar distractors. On the one hand, this can be explained by the finding that the eyes go more often to a distractor that looks like the target than to a distractor that does not look like it. On the other hand, the larger interference caused by the similar distractors is due to more difficulty disengaging the eyes from an object that looks like the target than from an object that looks quite different. The goal of the present study was to test whether these two processes (oculomotor capture and disengagement) are independent. We used a variant of the oculomotor capture paradigm. Participants were asked to make an eye movement to a gray target. Simultaneously with the target, we presented a green onset distractor. After a short delay (30-40 ms), the distractor changed either to gray (target-similar color) or to red (dissimilar color). Results show a clear dissociation between oculomotor capture and disengagement. Whereas there were only small differences in the percentage of capture, dwell times on the distractor were substantially longer when the distractor changed to the target-similar color. If, however, the color change occurred later in time (60-80 ms), this similarity effect in dwell times was gone as well. The latter finding is discussed in terms of rapid disengagement of covert attention from the distractor site and a critical time window for the influence of distractor characteristics on gaze dwell times.