Universitäts-Augenklinik, Freiburg, Germany.
Ophthalmic Physiol Opt. 2012 Jul;32(4):308-16. doi: 10.1111/j.1475-1313.2012.00917.x.
Binocular vision provides a considerable advantage over monocular vision when stationary particles partly obstruct the view. Such situations occur in real life, e.g., when drivers are trying to identify objects through a windshield dotted with snowflakes. In the process of driving, any bumpiness of the road will bring about a parallactic movement of particles on the windshield with respect to the visual object. We investigated whether this parallactic movement diminishes the advantage of binocular over monocular vision.
Using computer graphics, we simulated a driving situation with snowflakes represented by noise particles on the windshield. Ten observers tried to identify a Landolt ring (8 possible orintations, gap always 2.5 arcmin) presented for 2 s at a viewing distance of 2 m. The partly obstructing noise particles, either stationary or moving vertically at three sinusoidal velocities, were presented at a viewing distance of 0.8 m, corresponding to a stereodisparity well beyond Panum's fusional area. We compared the percentage of correct responses and the reaction time between binocular and monocular vision.
When the 'snowflakes' were stationary, binocular vision yielded more correct responses than monocular vision (52.2 ± 1.8% vs 39.7 ± 1.7%). When the 'snowflakes' were moving, the task was much easier and the binocular advantage less pronounced (95.8 ± 1.4% vs 85.3 ± 5.2%). The reaction time with stationary noise was 1.25 s for binocular and 1.31 s for monocular vision. With moving noise, averaged over all three velocities, the reaction time was 1.23 s for binocular and 1.36 s for monocular vision.
Parallactic movement of partly obstructing particles reduces the advantage of binocular over monocular vision to practically irrelevant values.
当静止的粒子部分遮挡视线时，双目视觉比单目视觉具有很大的优势。在现实生活中会出现这种情况，例如，当驾驶员试图通过布满雪花的挡风玻璃识别物体时。在驾驶过程中，道路的任何颠簸都会导致挡风玻璃上的粒子相对于视觉物体产生视差运动。我们研究了这种视差运动是否会降低双目视觉相对于单目视觉的优势。
使用计算机图形学，我们模拟了一种带有挡风玻璃上噪声粒子的雪花的驾驶情况。十个观察者试图识别一个 Landolt 环（8 个可能的方向，缺口始终为 2.5 弧分），在 2 米的观看距离下呈现 2 秒。部分遮挡的噪声粒子，无论是静止的还是以三种正弦速度垂直运动的，都在 0.8 米的观看距离下呈现，对应于超出 Panum 融合区的立体视差。我们比较了双眼和单眼视觉的正确响应百分比和反应时间。
当“雪花”静止时，双眼视觉比单眼视觉产生更多的正确响应（52.2 ± 1.8% vs 39.7 ± 1.7%）。当“雪花”移动时，任务变得容易得多，双眼优势不那么明显（95.8 ± 1.4% vs 85.3 ± 5.2%）。静止噪声的反应时间为双眼 1.25 秒，单眼 1.31 秒。对于所有三种速度的平均移动噪声，反应时间为双眼 1.23 秒，单眼 1.36 秒。
部分遮挡粒子的视差运动将双目视觉相对于单目视觉的优势降低到实际上无关紧要的值。
