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 three-dimensional (3D) scenes comprising pictorial depth information. Peripheral cues and targets appeared on top of 3D rectangular boxes placed on the surface of a textured ground plane in virtual space. When the target appeared at a farther location than the cue, the magnitude of the IOR effect in the 3D condition remained similar to the values found in the two-dimensional (2D) control condition (IOR was depth-blind). When the target appeared at a nearer location than the cue, the magnitude of the IOR effect was significantly attenuated (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 even in 3D scenes consisting entirely of pictorial depth information.