Komatsu H, Ideura Y, Kaji S, Yamane S
Neuroscience Section, Electrotechnical Laboratory, Ibaraki, Japan.
J Neurosci. 1992 Feb;12(2):408-24. doi: 10.1523/JNEUROSCI.12-02-00408.1992.
We tested the color selectivity of neurons in the inferior temporal (IT) cortex of two awake macaque monkeys. A color stimulus was presented at the center of the visual field while the animal performed a fixation task. The responses of single units to various colors were recorded and were plotted in a color space. The color space was based on the CIE (Commission Internationale de l'Eclairage) chromaticity diagram. Quantitative analysis of the color selectivity was performed using a standard set of colors that were evenly distributed in the color space. Sixty-five neurons recorded from eight guide tubes implanted in anterior part of IT cortex were tested quantitatively, and their color selectivity was statistically evaluated. Forty-six of them (71%) were classified as color selective. Color-selective cells responded to some colors but not to others, and we called the responsive region in the color space the "color field." The location and the size of a cell's color field were largely independent of the luminance of the stimulus. About 80% of the color-selective neurons had color fields consisting of a single responsive region that were restricted in some part of the color space, and the remaining cells had more than one responsive region within the color space. Preferred hues of the color-selective neurons differed from cell to cell. The population of cells together covered nearly all of the color space. There was a tendency for more color-selective cells to be less sensitive to white and desaturated cyans. Some of the cells with color fields that consisted of more than one responsive region were more sensitive to saturation of the stimulus than to its hue. Although previous electrophysiological studies in IT cortex emphasized the pattern selectivity of the neurons, our results suggest that color is an important factor in the role that IT cortex plays in the object recognition.
我们测试了两只清醒猕猴颞下（IT）皮质中神经元的颜色选择性。在动物执行注视任务时，在视野中心呈现颜色刺激。记录单个神经元对各种颜色的反应，并绘制在颜色空间中。该颜色空间基于国际照明委员会（CIE）色度图。使用在颜色空间中均匀分布的一组标准颜色对颜色选择性进行定量分析。对从植入IT皮质前部的八个导管中记录的65个神经元进行了定量测试，并对它们的颜色选择性进行了统计评估。其中46个（71%）被归类为颜色选择性神经元。颜色选择性细胞对某些颜色有反应，但对其他颜色没有反应，我们将颜色空间中的反应区域称为“颜色场”。细胞颜色场的位置和大小在很大程度上与刺激的亮度无关。约80%的颜色选择性神经元具有由单个反应区域组成的颜色场，这些区域在颜色空间的某些部分受到限制，其余细胞在颜色空间内有多个反应区域。颜色选择性神经元的偏好色调因细胞而异。这些细胞群体共同覆盖了几乎整个颜色空间。存在一种趋势，即更多的颜色选择性细胞对白色和不饱和青色不太敏感。一些具有由多个反应区域组成的颜色场的细胞对刺激的饱和度比对其色调更敏感。尽管之前在IT皮质进行的电生理研究强调了神经元的模式选择性，但我们的结果表明，颜色是IT皮质在物体识别中所起作用的一个重要因素。
