Rose D, Blake R
Department of Psychology, University of Surrey, UK.
Philos Trans R Soc Lond B Biol Sci. 1998 Jun 29;353(1371):967-80. doi: 10.1098/rstb.1998.0261.
When human observers view dynamic random noise, such as television 'snow', through a curved or annular aperture, they experience a compelling illusion that the noise is moving smoothly and coherently around the curve (the 'omega effect'). In several series of experiments, we have investigated the conditions under which this effect occurs and the possible mechanisms that might cause it. We contrast the omega effect with 'phi motion', seen when an object suddenly changes position. Our conclusions are that the visual scene is first segmented into objects before a coherent velocity is assigned to the texture on each object's surface. The omega effect arises because there are motion mechanisms that deal specifically with object rotation and these interact with pattern mechanisms sensitive to curvature.
当人类观察者通过弯曲或环形孔径观看动态随机噪声（如电视“雪花”）时，他们会体验到一种强烈的错觉，即噪声正沿着曲线平滑且连贯地移动（“欧米伽效应”）。在一系列实验中，我们研究了这种效应出现的条件以及可能导致它的机制。我们将欧米伽效应与物体突然改变位置时出现的“似动现象”进行对比。我们的结论是，在为每个物体表面的纹理赋予连贯速度之前，视觉场景首先会被分割成物体。欧米伽效应的出现是因为存在专门处理物体旋转的运动机制，这些机制与对曲率敏感的图案机制相互作用。
