Ratzlaff Michael, Nawrot Mark
Center for Visual and Cognitive Neuroscience, Department of Psychology, North Dakota State University, Fargo, ND, USA.
Center for Visual and Cognitive Neuroscience, Department of Psychology, North Dakota State University, Fargo, ND, USA
Perception. 2016 Sep;45(9):991-1007. doi: 10.1177/0301006616643679. Epub 2016 Apr 7.
The visual system uses an extraretinal pursuit eye movement signal to disambiguate the perception of depth from motion parallax. Visual motion in the same direction as the pursuit is perceived nearer in depth while visual motion in the opposite direction as pursuit is perceived farther in depth. This explanation of depth sign applies to either an allocentric frame of reference centered on the fixation point or an egocentric frame of reference centered on the observer. A related problem is that of depth order when two stimuli have a common direction of motion. The first psychophysical study determined whether perception of egocentric depth order is adequately explained by a model employing an allocentric framework, especially when the motion parallax stimuli have common rather than divergent motion. A second study determined whether a reversal in perceived depth order, produced by a reduction in pursuit velocity, is also explained by this model employing this allocentric framework. The results show than an allocentric model can explain both the egocentric perception of depth order with common motion and the perceptual depth order reversal created by a reduction in pursuit velocity. We conclude that an egocentric model is not the only explanation for perceived depth order in these common motion conditions.
视觉系统利用视网膜外追踪眼动信号来消除由运动视差产生的深度感知歧义。与追踪方向相同的视觉运动在深度上被感知为更近，而与追踪方向相反的视觉运动在深度上被感知为更远。这种深度信号的解释适用于以注视点为中心的异心参照系或以观察者为中心的自我参照系。一个相关的问题是当两个刺激具有共同的运动方向时的深度顺序问题。第一项心理物理学研究确定，采用异心框架的模型是否能充分解释自我中心深度顺序的感知，特别是当运动视差刺激具有共同而非发散的运动时。第二项研究确定，由追踪速度降低导致的深度顺序感知逆转，是否也能用采用这种异心框架的模型来解释。结果表明，异心模型既能解释共同运动时自我中心深度顺序的感知，也能解释由追踪速度降低产生的感知深度顺序逆转。我们得出结论，在这些共同运动条件下，自我中心模型并不是感知深度顺序的唯一解释。
