The dIOVD stimulus consisted of two clouds of dots: one presented to the left the other presented to the right eye. The two clouds were un-correlated between the eyes, and the dots in each cloud moved into opposite directions. In the dIOVD stimulus dots did not wrap because no dot had a defined disparity since by design there were no corresponding dots in the two eyes. Monocularly, dot motion in the three types of stimuli was similar, but they differed in the correlation of the dots between the two eyes. The nominally ‘correct’ direction of motion-in-depth for an IOVD random-dot stereogram is chosen to be consistent with the corresponding FULL cue random-dot stereogram, i.e., if one takes a FULL cue random-dot stereogram whose change in disparity signals motion away from the participant, the dots in each eye move in opposite directions towards the nose. Therefore, an IOVD stimulus with nasally moving dots is consistent with motion away from the participant, while temporally moving dots should signal motion towards the participant.