Transsaccadic Memory: A Postsaccadic Gap Enhances the Perception of Intrasaccadic Object Changes Differently for Dorsal and Ventral Representations

Abstract

We previously demonstrated that an intrasaccadic displacement of an object is reported with higher accuracy when the object is momentarily blanked after the saccade (Deubel, Schneider, and Bridgeman Vision Research in press). Here we tested whether the blanking manipulation (size of gap between onset of saccade and change in stimulus) also improves the perception of intrasaccadic changes with respect to size, luminance, orientation, colour, and shape. The task required subjects to saccade to a peripheral target. The saccade triggered a change in an attribute of the target (eg size of the saccade target) and subjects had to report this intrasaccadic change (eg whether the postsaccadic target was larger or smaller). The results indeed show for dorsal attributes (eg size, orientation)—generally used for spatio-motor actions like grasping—that the blanking manipulation improved performance (report of intrasaccadic changes). However, ventral attributes (eg colour)—used by the object recognition system—did not profit from the postsaccadic gap. The findings are discussed in relation to the kind of temporary object representations that are implemented across the saccade and how these are updated.