Masuda Osamu, Uchikawa Keiji
Department of Information Processing, Tokyo Institute of Technology, G2-1, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502, Japan.
Vision Res. 2009 Mar;49(6):622-36. doi: 10.1016/j.visres.2009.01.013. Epub 2009 Feb 4.
We measured the temporal summation properties of paired flashes to investigate the temporal responses of the chromatic channel in peripheral vision in comparison with those of the luminance channel. The size of the stimulus was scaled according to the cortical magnification factor. The temporal response was biphasic to complementary-chromatic pulse pairs, and was accelerated in peripheral vision in the same way as luminance pulse pairs. On the other hand, the temporal response was monophasic to same-chromatic pulse pairs, and was decelerated in the periphery. We proposed a model of the chromatic channel in which biphasic and monophasic internal channels were arranged in parallel. The sensitivity of the biphasic channel at high temporal frequency in the periphery was comparable to that in the fovea, whereas the sensitivity of the monophasic channel at low temporal frequency in the periphery matched that in the fovea. Similar results were obtained with pairs of flashed chromatic Gabor patches with their spatial frequencies scaled according to the cortical magnification factor. The inhibition phase of the biphasic channel was degraded with the spatial carrier frequency of the Gabor patch. The properties of the biphasic channel were consistent with the double duty hypothesis, while those of the monophasic channel were consistent with the two-channel hypothesis. The biphasic channel may correspond to the parvocellular pathway and the monophasic channel may reflect the properties of the koniocellular pathway.
我们测量了成对闪光的时间总和特性，以研究周边视觉中颜色通道与亮度通道相比的时间响应。刺激的大小根据皮质放大因子进行缩放。对于互补色脉冲对，时间响应是双相的，并且在周边视觉中与亮度脉冲对一样加速。另一方面，对于同色脉冲对，时间响应是单相的，并且在周边区域减速。我们提出了一个颜色通道模型，其中双相和单相内部通道并行排列。周边区域中双相通道在高时间频率下的灵敏度与中央凹中的灵敏度相当，而周边区域中单相通道在低时间频率下的灵敏度与中央凹中的灵敏度匹配。对于空间频率根据皮质放大因子缩放的成对闪光彩色伽柏补丁，也获得了类似的结果。双相通道的抑制阶段随着伽柏补丁的空间载波频率而退化。双相通道的特性与双重职责假说一致，而单相通道的特性与双通道假说一致。双相通道可能对应于小细胞通路，而单相通道可能反映了侏儒细胞通路的特性。
