Inhibition of Return in a 3D Scene Depends on the Direction of Depth Switch Between Cue and Target

Inhibition of Return (IOR) is a phenomenon that reflects slower target detection when the target appears at a previously cued rather than uncued location. In the present study, we investigated the extent to which IOR occurs in 3D scenes comprised of pictorial depth cues. Peripheral cues and targets appeared on top of 3D rectangular boxes placed on the surface of a textured ground plane in virtual space. It was revealed that when the target appeared at a farther location than the cue, the magnitude of the lateral IOR effect remained similar regardless of whether cues and targets appeared at different depths (i.e., IOR was depth-blind). When the target appeared at a nearer location than the cue, the magnitude of the lateral IOR effect was significantly attenuated (i.e., IOR was depth-specific). The present findings address inconsistencies in the literature on the effect of depth on IOR and support the notion that visuospatial attention exhibits a near space advantage.