Brooks Kevin R, Gillam Barbara J
School of Psychology, University of New South Wales, Sydney, NSW, Australia.
J Vis. 2007 Oct 11;7(13):1.1-14. doi: 10.1167/7.13.1.
Under usual circumstances, motion in depth is associated with conventional stereomotion cues: a change in disparity and differences between object velocities in each monocular image. However, occasionally these cues are unavailable due to the fact that in one eye the object may be occluded by, or camouflaged against appropriately positioned binocular objects. We report two experiments concerned with stereomotion perception under conditions of monocular camouflage. In Experiment 1, the visible half-image of a monocularly camouflaged object translated laterally. In this binocular context, percepts of lateral motion and motion in depth were equally consistent with the stimulus. Subjects perceived an oblique trajectory of 3D motion, compared to the more direct 3D trajectory experienced for binocularly matched stimuli. In Experiment 2, the perceived velocity of stereomotion was assessed. Again, for the stimulus used in Experiment 1, perceived stereomotion speed was lower than that for matched stimuli. However, when additional background objects were present, tightening the ecological constraints, perceived stereomotion velocity was often equivalent to that for matched stimuli. These results demonstrate for the first time that the motion of a monocularly camouflaged object can result in the perception of stereomotion, and that the perceived trajectory and speed are influenced by the ecological constraints of binocular geometry.
在通常情况下，深度运动与传统的立体运动线索相关联：视差的变化以及每个单眼图像中物体速度之间的差异。然而，偶尔由于以下事实这些线索不可用：在一只眼睛中，物体可能被适当定位的双眼物体遮挡或伪装。我们报告了两项关于单眼伪装条件下立体运动感知的实验。在实验1中，单眼伪装物体的可见半图像横向平移。在这种双眼情境中，横向运动和深度运动的感知与刺激同样一致。与双眼匹配刺激所经历的更直接的三维轨迹相比，受试者感知到三维运动的倾斜轨迹。在实验2中，评估了立体运动的感知速度。同样，对于实验1中使用的刺激，感知到的立体运动速度低于匹配刺激的速度。然而，当存在额外的背景物体时，收紧生态约束，感知到的立体运动速度通常与匹配刺激的速度相当。这些结果首次证明，单眼伪装物体的运动会导致立体运动的感知，并且感知到的轨迹和速度受双眼几何结构的生态约束影响。
