PDF(Pubmed)
Abstract：
Image differences between the eyes can cause interocular discrepancies in the speed of visual processing. Millisecond-scale differences in visual processing speed can cause dramatic misperceptions of the depth and three-dimensional direction of moving objects. Here, we develop a monocular and binocular continuous target-tracking psychophysics paradigm that can quantify such tiny differences in visual processing speed. Human observers continuously tracked a target undergoing Brownian motion with a range of luminance levels in each eye. Suitable analyses recover the time course of the visuomotor response in each condition, the dependence of visual processing speed on luminance level, and the temporal evolution of processing differences between the eyes. Importantly, using a direct within-observer comparison, we show that continuous target-tracking and traditional forced-choice psychophysical methods provide estimates of interocular delays that agree on average to within a fraction of a millisecond. Thus, visual processing delays are preserved in the movement dynamics of the hand. Finally, we show analytically, and partially confirm experimentally, that differences between the temporal impulse response functions in the two eyes predict how lateral target motion causes misperceptions of motion in depth and associated tracking responses. Because continuous target tracking can accurately recover millisecond-scale differences in visual processing speed and has multiple advantages over traditional psychophysics, it should facilitate the study of temporal processing in the future.
摘要：
眼睛之间的图像差异会导致视觉处理速度的眼间差异。视觉处理速度的毫秒级差异会导致对运动对象的深度和三维方向的严重误解。这里,我们开发了单目和双目连续目标跟踪心理物理学范式，可以量化视觉处理速度的微小差异。人类观察者以每只眼睛中的一系列亮度水平连续地跟踪经历布朗运动的目标。适当的分析可以恢复每种情况下视觉运动反应的时间过程，视觉处理速度对亮度水平的依赖性，以及眼睛之间处理差异的时间演变。重要的是,使用直接的观察者内部比较，我们表明，连续目标跟踪和传统的强制选择心理物理方法提供了平均在几分之一毫秒内一致的两眼间延迟的估计。因此，视觉处理延迟保留在手的运动动力学中。最后,我们分析性地展示，并通过实验部分证实，两只眼睛的时间脉冲响应函数之间的差异预测了横向目标运动如何导致对深度运动和相关跟踪响应的误解。由于连续目标跟踪可以准确恢复毫秒级的视觉处理速度差异，并且相对于传统的心理物理学具有多种优势，它应该有助于将来对时间处理的研究。
