EYE MOVEMENTS IN THE PERCEPTION OF DEPTH FROM MOTION

从运动中感知深度可能是视觉加工的重要方面。 单目深度线索都很容易被欺骗，单目观察者或眼睛侧向放置的动物无法获得双眼立体视觉。然而，运动深度可能产生模糊的深度分配（例如，动态深度效应-KDE）或在运动视差的情况下的明确深度感知，即使视网膜信息在这两种情况下可能相同。 是什么让运动视差产生的深度变得清晰？ 虽然关于观察者头部运动方向的信息似乎是必要的，但目前的研究表明，视觉系统实际上使用缓慢的眼球运动信号来实现这一目的。 本项目将研究视觉系统完成这一任务的机制。 心理物理学实验将使用一个计算机系统，该系统能够整合来自线性头部跟踪系统和红外线眼睛跟踪系统的信息，从而可以监控头部和眼睛的位置。 该系统还可以呈现运动视差显示的立体版本（使用铁电快门系统），以便双目立体视觉可以用作与运动视差深度进行比较的控制。 实验将确定OKR或追踪眼球运动在从运动感知深度中的效用，包括以前模糊的条件，如KDE。此外，由于眼球运动幅度取决于观看距离，观看距离在运动视差显示器中的作用将被探索。 最后，如果运动视差深度依赖于缓慢的眼球运动，那么由于皮质或小脑病变而导致眼球运动功能障碍的患者应该表现出运动视差深度感知的问题。理论上的目标是开发一个单一的神经网络模型，可以解释从运动视差，运动透视，动力学深度，立体视觉和这些不同的深度线索之间的各种神经相互作用的深度感知。以前的神经网络模型（Nawrot和Blake，1991）仅限于动力学深度，立体视觉及其相互作用。眼动信号的增加将扩大模型的范围，以包括运动视差及其与双目立体视觉的各种相互作用。

The perception of depth from motion is perhaps the important aspect of visual processing. Monocular cues to depth are all easily deceived, and binocular stereopsis is not available to monocular observers or animals with laterally places eyes. However, depth from motion may produce either ambiguous depth assignments (e.g., kinetic depth effect-KDE) or unambiguous depth percepts in the case of motion parallax even though the retinal information may be the same in the two cases. What is it that makes depth from motion parallax unambiguous? While information about the direction of observer head movement appears necessary, current research shows that the visual system actually uses a slow eye movement signal for this purpose. This project will study the mechanism by which the visual system accomplishes this task. Psychophysical experiments will use a computer system capable of integrating information from a linear head-tracking system and an infra-red eye-tracking system so that both head and eye position can be monitored. This system can also present stereoscopic versions of the motion parallax displays (using ferroelectric shutter system) so that binocular stereopsis can be used as a control to which depth from motion parallax is compared. Experiments will determine the utility of OKR or pursuit eye movements in the perception of depth from motion, including previously ambiguous conditions such as KDE. Additionally, as eye movement magnitude depends on viewing distance, the role of viewing distance in motion parallax displays will be explored. Finally, if depth from motion parallax relies on slow eye movements, then patients with eye movement dysfunction due to cortical or cerebellar lesions should show problems in the perception of depth from motion parallax. The theoretical goal is to develop a single neural network model that can account for the perception of depth from motion parallax, motion perspective, kinetic depth, stereopsis and the various neural interactions between these different depth cues. The previous neural network model (Nawrot and Blake, 1991) was confined to kinetic depth, stereopsis, and their interaction. The addition of an eye movement signal would expand the scope of the model to include motion parallax and its various interactions with binocular stereopsis.