Tyler C W, Kontsevich L L
Smith-Kettlewell Eye Research Institute, San Francisco, CA 94115, USA.
Perception. 1995;24(2):127-53. doi: 10.1068/p240127.
Consideration of the range of phenomena from studies of human stereopsis suggests that a five-stage model is required to provide a complete account of the processes involved, within which any stereoattention mechanism must operate. The information from the disparity field of the optical projections to the two eyes (stage 1) goes to a set of parallel Keplerian arrays of disparity detectors, each array selective for a different spatiotemporal property of the visual images (stage 2). Global interactions produce a cyclopean depth image that is cleaned of the spurious ghost images in the Keplerian arrays (stage 3) and that may then be processed for its (hypercyclopean) from elements (stage 4). Finally, there must be a stage of integration of the stereoscopic depth cues with monocular and kinesthetic depth cues to form the overall map of perceived distance (stage 5). The fact that multiple cyclopean surfaces may be perceived as transparent implies that the stereoscopic system is not limited by a singular-surface constraint. However, it is unclear whether multiple surfaces can be seen simultaneously or whether only one surface is seen at a time by a selective-attention process, with the others perceived as a purely inchoate (qualitative) depth impression. New experiments on cueing of ambiguous stereocorrugations by singular flat planes suggest that selective stereoattention is a powerful mechanism. In fact, the results show that attention can be focused not just in horopteral planes but in a variety of depth configurations. Moreover, this attention focus may act as a tracking mechanism to allow perception of smooth cyclopean stereomotion, which has a frequency response up to approximately 5 Hz (in contrast to the approximately 15 Hz limit for detecting planar disparity shifts as jerky appearance and disappearance effects). Finally, the spatial limits of stereosurface reconstruction are explored with cyclopean targets to show some interesting asymmetries of the surface-wrapping process that may represent object-oriented constraints on depth reconstruction.
对人类立体视觉研究中一系列现象的思考表明，需要一个五阶段模型来完整解释其中涉及的过程，任何立体视觉注意机制都必须在这个模型中运行。来自双眼光学投影视差场的信息（第一阶段）会传送到一组视差探测器的平行开普勒阵列，每个阵列对视觉图像的不同时空特性具有选择性（第二阶段）。全局相互作用产生一个独眼巨人深度图像，该图像去除了开普勒阵列中的虚假重影图像（第三阶段），然后可以对其（超独眼巨人）元素进行处理（第四阶段）。最后，必须有一个阶段将立体深度线索与单眼和动觉深度线索整合起来，以形成感知距离的整体地图（第五阶段）。多个独眼巨人表面可能被视为透明的这一事实意味着立体视觉系统不受单一表面约束的限制。然而，目前尚不清楚多个表面是否能同时被看到，或者是否只有一个表面能通过选择性注意过程一次被看到，而其他表面则被视为纯粹不完整（定性）的深度印象。关于奇异平面提示模糊立体波纹的新实验表明，选择性立体视觉注意是一种强大的机制。事实上，结果表明注意力不仅可以聚焦在水平子午面上，还可以聚焦在各种深度配置上。此外，这种注意力焦点可能充当一种跟踪机制，以允许感知平滑的独眼巨人立体运动，其频率响应高达约5赫兹（相比之下，检测平面视差变化时出现的突然出现和消失效果的频率极限约为15赫兹）。最后，用独眼巨人目标探索了立体表面重建的空间限制，以展示表面包裹过程中一些有趣的不对称性，这些不对称性可能代表了对深度重建的面向对象约束。
