Inhibition of return: a “depth-blind” mechanism?

Four experiments investigated the Inhibition Of Return (IOR), in the three-dimensional and in the two-dimensional space. The first two experiments compared detection and discrimination tasks in eliciting IOR effects in a three-dimensional empty space. Two other experiments assessed the IOR effects in a scene that included two sets of objects (parallelepipeds extending in depth and parallelepipeds located at different depths, extending in the horizontal plane). In each experiment we compared the IOR effects in 2D (both with and without depth clues) and stereoscopic 3D conditions. Results showed IOR in 3D space, confirming that it is not a depth-blind mechanism.