Treutwein B, Rentschler I, Caelli T
Institut für Medizinische Psychologie der Universität, München Federal Republic of Germany.
Biol Cybern. 1989;60(4):285-95. doi: 10.1007/BF00204126.
We have investigated the discriminability of gratings which simultaneously vary in spatial frequency and orientation. Thirteen and nine reference gratings were used with two observers, and bivariate discrimination probability surfaces were determined around each grating. These data were then fitted to a general bivariate Gaussian function. The results clearly demonstrate local separability in this log frequency and orientation discrimination domain. Our results also show that the factor contributing most to the non-Euclidean nature of such frequency/orientation discrimination is orientation anisotropia, although we also find some evidence for smaller changes in the associated Riemannian line-element at different frequency ranges. These results cast doubt upon claims for a "pseudo line-element" for frequency discrimination based upon the nonlinear outputs of a fixed set of detectors.
我们研究了在空间频率和方向上同时变化的光栅的可辨别性。使用13个和9个参考光栅对两名观察者进行实验，并围绕每个光栅确定双变量辨别概率曲面。然后将这些数据拟合到一个通用的双变量高斯函数。结果清楚地表明在这个对数频率和方向辨别域中存在局部可分离性。我们的结果还表明，对这种频率/方向辨别非欧几里得性质贡献最大的因素是方向各向异性，尽管我们也发现了一些证据，表明在不同频率范围内相关的黎曼线元存在较小变化。这些结果对基于一组固定探测器的非线性输出而提出的频率辨别“伪线元”的说法提出了质疑。
