Spatiotemporal attentional constraints in perception

Abstract

Selection of objects and events to perceive the world around us is determined not purely on whatever salient objects or events stand out the strongest in the current flow of sensory input. Current goals, interests etcetera steer the perceptual system in a top-down manner by directing the senses to a particular part of the world as well. This thesis focuses on how well perception can be voluntary (top-down) controlled by examining the spatiotemporal limits of attentional selection. It was shown in this thesis that the temporal limits of attentional selection are finer than thus far reported (chapter 2-4). Whether attention can individuate objects or events in time apparently depends on a couple of factors, which are the ability to disengage attention in time, the number of features that need to be selected simultaneously and the timing or occurrence of the task-relevant event/object itself. For spatial limits of attentional selection (chapter 5) the critical spacing between objects might not determine whether attention can select objects across space, but rather the spatial frequency with which attention is distributed across space determines spatial attentional selection in perception.