Yang J, Makous W
Department of Psychology, University of Rochester, NY 14627.
Vision Res. 1994 Oct;34(19):2569-76. doi: 10.1016/0042-6989(94)90243-7.
Contrast sensitivity functions were measured in two ways: by counterphase modulation; and by in-phase modulation, in which the luminance of every point of a spatial grating was sinusoidally modulated in phase with one another. Contrast sensitivity functions measured by counterphase modulated gratings show spatiotemporal interactions that represent bandpass filtering. Contrast sensitivity functions measured by in-phase modulation are even more sharply bandpass in the spatial frequency domain, but they are spatiotemporally decoupled, i.e. the effects of spatial and temporal variables are separable. This difference can be explained by the composition of the frequency components of the counterphase and the in-phase modulated gratings and by masking between components. The results suggest that the intrinsic filters are low-pass exponentials, that they are spatiotemporally separable, and that the spatiotemporal interaction of counterphase gratings is best described as masking by the zero spatiotemporal frequency component of the test gratings.
通过反相调制；以及通过同相调制，其中空间光栅的每个点的亮度以彼此同相的方式进行正弦调制。由反相调制光栅测量的对比敏感度函数显示出代表带通滤波的时空相互作用。由同相调制测量的对比敏感度函数在空间频率域中具有更尖锐的带通特性，但它们在时空上是解耦的，即空间和时间变量的影响是可分离的。这种差异可以通过反相和同相调制光栅的频率成分组成以及成分之间的掩蔽来解释。结果表明，内在滤波器是低通指数函数，它们在时空上是可分离的，并且反相光栅的时空相互作用最好描述为被测试光栅的零时空频率成分掩蔽。
