Ahlström U, Börjesson E
Department of Psychology, University of Uppsala, Sweden.
Perception. 1996;25(3):279-91. doi: 10.1068/p250279.
A potential source of information about spatial layout, surface slant, and self-motion is provided by transformations of the optic flow field. Theoretical analyses have demonstrated that such flow fields can be decomposed into translation, rotation, expansion, and deformation components. The objective in this study was to investigate the effectiveness of these motions as visual primitives for preattentive scene segregation. The stimuli consisted of two-frame patterns containing 998 dots. A variable number of these dots (5 to 50) were defined as target dots, representing a specific motion structure, with the residual dots defined as a noise field. The observers' task was to identify the location and type of motion structure. On the basis of the number of target dots needed to detect and correctly identify the target structure, it was determined that translation was the most easily detected structure, followed by rotation, expansion, and compression. Deformation was found to have a detection threshold as high as compression. The results are related to other studies of these motion components.
光流场的变换提供了有关空间布局、表面倾斜和自身运动的潜在信息来源。理论分析表明，此类流场可分解为平移、旋转、扩展和变形分量。本研究的目的是调查这些运动作为预注意场景分割视觉基元的有效性。刺激物由包含998个点的两帧图案组成。这些点中的可变数量（5至50个）被定义为目标点，代表特定的运动结构，其余的点被定义为噪声场。观察者的任务是识别运动结构的位置和类型。根据检测和正确识别目标结构所需的目标点数，确定平移是最容易检测到的结构，其次是旋转、扩展和压缩。发现变形的检测阈值与压缩一样高。这些结果与关于这些运动分量的其他研究相关。
