Mind the Gap: The Cost of Looking at Nothing, or the Performance Implications of Memory-induced Attention Shifts

The visual indexing theory proposed by Zenon Pylyshyn predicts that visual attention mechanisms are employed when projecting mental images onto a visual scene. Recent eyetracking have supported this hypothesis by showing that people tend to look at empty places, where requested information has been previously presented. However it remained unclear what performance implications this behavior has. The present study aimed to explore how the relative location of presentation affects performance in tasks involving recalling whether an object has already been seen. Experiment 1 demonstrated that recalling objects which have been presented away from the current focus point results in slower reaction times. Experiment 2 showed that a spatial compatibility effect arises if the relative location of the memorized object is incompatible with a spatial task at hand.