Fernandez Julian Martin, Farell Bart
Institute for Sensory Research, Syracuse University, New York 13244-5290, USA.
Vision Res. 2006 Apr;46(8-9):1307-17. doi: 10.1016/j.visres.2005.10.025. Epub 2005 Dec 13.
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.
存在两种用于检测深度运动的双眼机制。一种基于随时间变化的视差，另一种基于两眼间的速度差异。此前已经表明，随时间变化的视差能够产生深度运动的感知。然而，关于两眼间速度差异在深度运动感知中是否起作用，现有的心理物理学和生理学数据尚无定论。我们使用运动后效来研究这个问题，运动后效是指在适应真实运动后静态图案产生的虚幻运动。我们对两只眼睛诱发了差异运动后效，然后用双眼观察静止随机点图案来测试深度运动。此前已经表明，差异平移运动后效会产生强烈的深度运动感知。我们在此表明，旋转运动后效会抑制这种深度运动感知，尽管真实的旋转会诱发深度运动。非水平平移运动后效不会抑制深度运动。总之，我们的结果有力地表明：（1）纯粹的两眼间速度差异能够产生深度运动；（2）运动后效引起的虚幻位置变化是在视觉层级中双眼组合之后相对较晚的时候产生的。
