Do reference surfaces influence exocentric pointing?

Abstract

All elements of the visual field are known to influence the perception of the egocentric distances of objects. Not only the ground surface of a scene, but also the surface at the back or other objects in the scene can affect an observer’s egocentric distance estimation of an object. We tested whether this is also true for exocentric direction estimations. We used an exocentric pointing task to test whether the presence of poster-boards in the visual scene would influence the perception of the exocentric direction between two test-objects. In this task the observer has to direct a pointer, with a remote control, to a target. We placed the poster-boards at various positions in the visual field to test whether these boards would affect the settings of the observer. We found that they only affected the settings when they directly served as a reference for orienting the pointer to the target.