Conway Bevil R, Hubel David H, Livingstone Margaret S
Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
Cereb Cortex. 2002 Sep;12(9):915-25. doi: 10.1093/cercor/12.9.915.
We explored the neural basis for spatial color contrast (red looks redder surrounded by green) and temporal color contrast (red looks redder if preceded by green) in primary visual cortex (V1) of the alert macaque. Using pairs of stimuli, we found a subset of neurons that gave stronger responses to sequences of red and green spots and stronger responses to adjacent red and green spots. These cells combined their cone inputs linearly: for a red-ON-center cell, the sum of the OFF response to green and the ON response to red predicted the peak response to red preceded by green. These 'color' cells, which could underlie hue discrimination because they show cone opponency, could mediate spatial and temporal color contrast. In contrast, the majority of cortical cells, which do not show overt cone opponency but which are often orientation tuned and/or direction selective, are by themselves incapable of mediating hue discrimination. The remarkable degree of specialization shown by cells in V1, especially that of the double-opponent color cells, is discussed.
我们在警觉猕猴的初级视皮层（V1）中探究了空间颜色对比（红色在绿色环绕下看起来更红）和时间颜色对比（红色如果之前是绿色则看起来更红）的神经基础。使用成对的刺激，我们发现了一部分神经元，它们对红色和绿色斑点序列的反应更强，对相邻的红色和绿色斑点的反应也更强。这些细胞将它们的视锥细胞输入进行线性组合：对于一个红色中心兴奋型细胞，对绿色的抑制反应和对红色的兴奋反应之和可预测红色之前为绿色时对红色的峰值反应。这些“颜色”细胞可能是色调辨别背后的机制，因为它们表现出视锥细胞拮抗作用，能够介导空间和时间颜色对比。相比之下，大多数皮层细胞本身不能介导色调辨别，它们不表现出明显的视锥细胞拮抗作用，但通常具有方向调谐和/或方向选择性。文中讨论了V1区细胞所表现出的显著专业化程度，尤其是双拮抗颜色细胞的专业化程度。
