Victor J D, Purpura K P, Conte M M
Department of Neurology and Neuroscience, Cornell University Medical College, New York, NY 10021, USA.
Vis Neurosci. 1998 Jul-Aug;15(4):607-24. doi: 10.1017/s0952523898154032.
We report VEP studies which delineate interactions between chromatic and luminance contrast signals. We examined responses to sinusoidal luminance gratings undergoing 4-Hz square-wave contrast reversal, upon which standing gratings with various admixtures of luminance and chromatic contrast were alternately superimposed and withdrawn. The presence of the standing grating induced a VEP component at the fundamental frequency of the contrast-reversal grating. This VEP component appeared without any appreciable lag, and did not vary in amplitude over the 4 s during which the standing grating was present. The observed fundamental response differed from the fundamental component that would be expected from the known interaction between the luminance component of the standing grating with the modulated grating (Bodis-Wollner et al., 1972; Bobak et al., 1988), in three ways: (1) The fundamental response was not nulled for standing gratings that were isoluminant or near-isoluminant. (2) The chromatic dependence of the fundamental response implied an S-cone input to the interaction. (3) No single mechanism (driven by a linear combination of cone signals) could account quantitatively for the size of this response, particularly when the standing grating strongly modulated two cones in phase.
我们报告了视觉诱发电位（VEP）研究，这些研究描绘了颜色和亮度对比信号之间的相互作用。我们检查了对经历4赫兹方波对比度反转的正弦亮度光栅的反应，在该光栅上交替叠加和撤去具有不同亮度和颜色对比度混合的固定光栅。固定光栅的存在在对比度反转光栅的基频处诱发了一个VEP成分。这个VEP成分出现时没有任何明显的延迟，并且在固定光栅存在的4秒内其幅度没有变化。观察到的基频反应与根据固定光栅的亮度成分与调制光栅之间已知的相互作用所预期的基频成分（博迪斯-沃尔纳等人，1972年；博巴克等人，1988年）在三个方面有所不同：（1）对于等亮度或近等亮度的固定光栅，基频反应并未抵消。（2）基频反应的颜色依赖性意味着该相互作用有S锥体输入。（3）没有单一机制（由锥体信号的线性组合驱动）能够定量解释这种反应的大小，特别是当固定光栅同相强烈调制两个锥体时。
