Cumming B G
University Laboratory of Physiology, Oxford, UK.
Perception. 1995;24(1):105-14. doi: 10.1068/p240105.
There are in principle at least two binocular sources of information that could be used to determine the motion of an object towards or away from an observer; such motion produces changes in binocular disparities over time and also generates different image velocities in the two eyes. It has been argued in the past that stereomotion is detected by a mechanism that is independent of that which detects static disparities. More recently this conclusion has been questioned. If stereomotion detection in fact depends upon detecting disparities, there should be a clear correlation between static stereo-detection thresholds and stereomotion thresholds. If the systems are separate, there need be no such correlation. Four types of threshold measurement were performed by means of random-dot stereograms: (1) static stereo detection/discrimination; (2) stereomotion detection in random-dot stereograms (temporally uncorrelated); (3) stereomotion detection in temporally correlated random-dot stereograms; and (4) binocular detection of frontoparallel motion. Three normal subjects and five subjects with unusually high stereoacuities were studied. In addition, two manipulations were performed that altered stereomotion thresholds: changes in mean disparity, and image defocus produced by positive spectacle lenses. Across subjects and conditions, stereomotion thresholds were well correlated with stereo-discrimination thresholds. Stereomotion was poorly correlated with binocular frontoparallel-motion thresholds. These results suggest that stereomotion is detected by means of registering changes in the output of the same disparity detectors that are used to detect static disparities.
原则上，至少有两种双目信息源可用于确定物体相对于观察者的朝向或远离运动；这种运动会随时间产生双目视差变化，并且在两只眼睛中产生不同的图像速度。过去有人认为，立体运动是由一种独立于检测静态视差的机制检测到的。最近，这一结论受到了质疑。如果立体运动检测实际上依赖于对视差的检测，那么静态立体检测阈值和立体运动阈值之间应该有明显的相关性。如果这两个系统是分开的，就不需要这种相关性。通过随机点立体图进行了四种类型的阈值测量：（1）静态立体检测/辨别；（2）随机点立体图中的立体运动检测（时间上不相关）；（3）时间相关的随机点立体图中的立体运动检测；以及（4）双目检测额状面平行运动。研究了三名正常受试者和五名具有异常高立体视敏度的受试者。此外，还进行了两种改变立体运动阈值的操作：平均视差的变化，以及正镜片产生的图像散焦。在不同受试者和条件下，立体运动阈值与立体辨别阈值高度相关。立体运动与双目额状面平行运动阈值的相关性较差。这些结果表明，立体运动是通过记录用于检测静态视差的相同视差探测器输出的变化来检测的。
