Abstract
Visual exploration of a scene relies on the frequent execution of saccadic eye movements. At the retinal level, this implies that the projection of the scene constantly undergoes large, rapid displacements. Yet, the human perceptual experience is stable and continuous. A long-standing question is then whether visual object representations constructed before a saccade can be retained until after saccade landing, and if so, whether this transsaccadic representation is subsequently employed in postsaccadic processing of the same object. In the present study we show that this is indeed the case for image-abstracted yet detailed representations of visual form. Specifically, subjects glimpsed a closed contour defined by the perceptual grouping (by similarity) of spatially separated local elements in the periphery of the visual field, and made a saccadic eye movement towards it. After saccade landing this preview information was observed to affect the perceptual grouping speed of a second closed contour in the same spatiotopic location, despite an intrasaccadic change to the grouping principle defining it (good continuation instead of similarity). This yielded a benefit for an identical preview and a cost for a different but well-defined preview contour, compared to a baseline condition where only vaguely defined form information was contained within the preview display. In addition, it was found that the presaccadic presence of such a vaguely defined preview object by itself already decreased the speed of postsaccadic object contour grouping, relative to conditions in which unstructured preview displays were presented. We conclude that the visual system pools its local feature information across space, cues, and time into transsaccadically persistent object form representations, providing a robust basis for the integration of detailed shape information as well as perceptual continuity across saccades.
This research was supported by the Concerted Research Effort Convention GOA of the Research Fund K.U. Leuven (GOA/2005/03-TBA) granted to Géry d'Ydewalle, Karl Verfaillie, and Johan Wagemans, by the European Community through GazeCom project IST-C-033816 to Karl Verfaillie and Peter De Graef, and by a Methusalem grant to Johan Wagemans (METH/08/02).