Coding of identity-diagnostic information in transsaccadic object perception.

In four experiments, we examined the hypothesis that a presaccadic extrafoveal preview of an object normally affects subsequent postsaccadic foveal processing of the object. On each trial, viewers inspected an array of three objects and were instructed to remember one object characteristic (in-depth orientation, image-plane orientation, color, or semantic category). During the saccade to one of the objects, an intrasaccadic change in the in-depth orientation or the color could occur and its effect on gaze duration on the object was analyzed. When participants were instructed to remember the objects' depth orientation, gaze durations increased after an intrasaccadic depth rotation but not after a color change, demonstrating task dependence. Color information was only integrated when it was task relevant (i.e., when it had to be remembered). When the task required access to stored object models (categorizing the object or deciding whether it was upright or inverted), an intrasaccadic depth rotation again prolonged gaze durations, even though there was no explicit instruction to remember the objects' depth orientation. This suggests that orientation-dependent object models are accessed during object perception across saccades and that transsaccadic integration serves to expedite object identification through the integration of presaccadic and postsaccadic object-diagnostic information.