Motion in depth from interocular velocity differences revealed by differential motion aftereffect

Abstract

There are two possible binocular mechanisms for the detection of motion in depth. One is based on disparity changes over time and the other is based on interocular velocity differences. It has previously been shown that disparity changes over time can produce the perception of motion in depth. However, existing psychophysical and physiological data are inconclusive as to whether interocular velocity differences play a role in motion in depth perception. We studied this issue using the motion aftereffect, the illusory motion of static patterns that follows adaptation to real motion. We induced a differential motion aftereffect to the two eyes and then tested for motion in depth in a stationary random-dot pattern seen with both eyes. It has been shown previously that a differential translational motion aftereffect produces a strong perception of motion in depth. We show here that a rotational motion aftereffect inhibits this perception of motion in depth, even though a real rotation induces motion in depth. A non-horizontal translational motion aftereffect did not inhibit motion in depth. Together, our results strongly suggest that (1) pure interocular velocity differences can produce motion in depth, and (2) the illusory changes in position from the motion aftereffect are generated relatively late in the visual hierarchy, after binocular combination.

To CD or not to CD: Is there a 3D motion aftereffect based on changing disparities?

“…This, along with a spate of recent papers by several other groups (e.g., Brooks, 2002; Fernandez & Farell, 2006; Nefs, O’Hare, & Harris, 2010; Shioiri, Kakehi, Tashiro, & Yaguchi, 2009, Shioiri, Nakajima, Kakehi, & Yaguchi, 2008), is an important convergence of evidence because the IOVD mechanism is a radically different kind of binocular computation; one that is distinct from the long-appreciated mechanism of stereopsis, and its confirmed existence has important theoretical and practical consequences for vision science.…”

Binocular vision

“…A subsequent study supported the use of monocular velocity signals for motion in depth processing using the motion aftereffect (Fernandez & Farell, 2006). Only one eye was adapted to motion of an RD kinematogram, thus eliminating any changing disparity signals.…”

Binocular Mechanisms of 3D Motion Processing

“…By exploiting incomplete interocular transfer of monocular motion aftereffect (MAE) (Mitchell et al 1975), an illusory IOVD cue can be induced by means of unequal motion aftereffect magnitudes in the two eyes (Brooks 2002b, Fernandez & Farell 2006). Unlike 2D MAEs, 3D components of IOVD-based MAEs were robust to differences in the spatial frequency of adaptation and test stimuli, suggesting independent spatiotemporal integration for 2D and 3D motion processing (Shioiri & Matsumiya 2009).…”