ORIENTATIONAL ANISOTROPY IN THE HUMAN VISUAL-SYSTEM
ORIENTATIONAL ANISOTROPY IN THE HUMAN VISUAL-SYSTEM
复制标题
DOI：
10.3758/bf03202846
复制
发表时间：
1985-01-01
期刊：
影响因子：
--
通讯作者：
JENKINS, B
中科院分区：
文献类型：
--
作者：
JENKINS, B
使用全局模式/随机性阈值来研究人类视觉系统中的方向各向异性。使用动态转置对称纹理，因为它们允许独立和交互地研究 3 个理论上导出的变量：尺寸、方向均匀性和数量。由这些阈值索引的相关性的可检测性取决于均匀点对元素Δd的大小及其方向；在垂直子午线中发现了较大的容许Δd值。增加刺激场大小会增加该阈值的绝对值，但不会增加作为方向函数的相对值。阈值还取决于点对的方向均匀性。在超过临界点对尺寸之前，可容忍的扰动不会随着均匀方向的变化而变化。这个临界点对的大小确实随着方向的变化而变化，从垂直到水平到倾斜的变化非常明显。构成纹理的点对元素的数量不影响全局图案/随机性阈值。研究了这些数据对“倾斜效应”背后的神经机制的影响。方向各向异性可能存在于服务于对方向选择性敏感的功能单元的感受野的长度中。仅这个因素无法解释视觉中方向各向异性的各种例子。人类视觉中测量到的任何各向异性可能是人类视觉系统中各个处理级别内部和之间存在 > 1 各向异性的净产物。
A global pattern/randomness threshold was used to investigate orientational anisotropy in the human visual system. Dynamic transpositionally symmetric textures were used, since they allowed the investigation of 3 theoretically derived variables, size, orientational uniformity and numerosity, independently and in interaction. The detectability of correlation, as indexed by these thresholds, was dependent on the size of the uniform point-pair elements, .DELTA.d, and their orientation; larger tolerable .DELTA.d values were found in the vertical meridian. Increasing the stimulus field size increased the absolute value of this threshold, but not the relative value as a function of orientation. The thresholds were also dependent on the orientational uniformity of the point-pairs. Tolerable perturbation did not vary as a function of the uniform orientation until a critical point-pair size was exceeded. This critical point-pair size did vary as a function of orientation, falling quite distinctly from vertical, to horizontal, to oblique. The number of point-pair elements comprising the textures did not affect the global pattern/randomness threshold. The implications of these data for the neural mechanisms underlying the "oblique effect" were examined. An orientational anisotropy might exist in the length of receptive fields serving functional units selectively sensitive to orientation. This factor alone could not account for the various examples of the orientational anisotropy in vision. Any anisotropy measured in human vision might be the net product of > 1 anisotropy existing within and between the various levels of processing in the human visual system.