Attentional Distribution Affects Motion-Induced Blindness

In motion-induced blindness (MIB) salient static dots "disappear" when superimposed onto a moving mask. In this article, the modulating effect of voluntary task-divided attention on MIB disappearances is investigated. Two types of tasks were used in turn as the primary and the secondary ones: to detect target dots disappearances (the MIB task) and to detect subjective changes in the direction of mask rotation caused by the motion aftereffect (the MAE task). Thus the allocation of central attention was manipulated while the MIB display remained unchangeable. The focused attention condition (a single task to detect MIB disappearances) and two divided attention conditions (detecting MIB as primary and secondary tasks) were compared. In the focused attention condition, detection of MIB disappearances had the highest task priority and evoked the greatest number of disappearances. The allocation of attention to different tasks led to the dramatic decrease of MIB occurrences and the more so the more priority the second (MAE) task had.