STEREOACUITY AND BINOCULAR CORRESPONDENCE

描述：（改编自研究者摘要）：立体视觉，一种 关于物理距离的重要信息来源，取决于 人类对双眼视差的反应能力。 视差是如何编码的 人类的视觉系统？ 大量的电生理和 心理物理学数据表明，有一个特殊的差距系统中， 灵长类动物的大脑皮层，但结合这两个单眼的确切机制， 信号是未知的。 我们提出了一系列的心理物理学 测试“原始”视差系统的机械模型的实验， 在视觉早期发现的简单局部探测器模型 处理. 基于对对比敏感度的广泛了解， 在过去三十年积累的空间视觉，这个模型可以 考虑到先前的立体视敏度的心理物理测量， 差异歧视，包括本实验室产生的一些差异歧视，以及 它确实模仿了单个皮层单位的调谐特性， 对差异敏感。 该模型不能解决“双目 对应”问题，也不考虑高阶相互作用 发生在整个视野的局部视差检测器之间。 其他实验将检查这些高阶的影响 交互. 差异通常被认为是有用的， 比如Julesz著名的随机点立体图 有多好 差异本身定义视觉形式？ 差异的逐渐变化（平滑 在深度上倾斜的表面）可能很难看到。 这是因为 相邻探测器之间的抑制性相互作用？ 最后一系列的实验将探索 假设的双眼和单眼机制。 我们使用测量 空间定位（超敏），以研究 正常观察者的双眼和单眼信号。 在立体异常 和弱视的观察者，有显着的缺陷，双眼 处理可能是由于单目信号之间的不平衡 从两只眼睛里发出的。 因此，计划进行实验以研究 立体异常观察者的双眼-单眼竞争。

DESCRIPTION: (Adapted from the Investigator's abstract): Stereopsis, an important source of information about physical distance, depends on the human ability to respond to binocular disparity. How is disparity encoded by the human visual system? A substantial body of electrophysiological and psychophysical data shows that there is a special disparity system in the primate cortex, but the exact mechanism for combining the two monocular signals is as yet unknown. We propose a series of psychophysical experiments to test a mechanistic model of a "primitive" disparity system, a model for simple local detectors found in early stages of visual processing. Based on the vast knowledge of contrast sensitivity and spatial vision accumulated over the past three decades, this model can account for previous psychophysical measurements of stereoacuity and disparity discrimination, including some generated by this laboratory, and it does mimic the tuning characteristics of single cortical units that are sensitive to disparity. This model does not solve the "binocular correspondence" problem, nor does it account for higher order interactions occurring between local disparity detectors across the visual field. Additional experiments will examine the effects of these higher order interactions. Disparity is often thought to be useful in breaking camouflage as in Julesz' famous random dot stereograms. How well does disparity per se define visual forms? Gradual changes in disparity (smooth surfaces tilted in depth) can be very difficult to see. Is this because of inhibitory interactions between adjacent detectors? A final series of experiments will explore the relationship between postulated binocular and monocular mechanisms. We use measurements of spatial localization (hyperacuity) to study the competition between binocular and monocular signals in normal observers. In stereoanomalous and amblyopic observers, there are significant deficiencies in binocular processing probably due to an imbalance between the monocular signals coming from the two eyes. Therefore, experiments are planned to study the binocular-monocular competition in stereoanomalous observers.