Fig. 3

Representation of color by color-selective neurons in color patches. a Responses of all color-selective neurons averaged across stimuli within each category to images of 8 different hues, together with gray (left-most column) and natural color (right most-column), sorted in the same way as Fig. 2. b Neural representation of colors in the activities of color-selective neurons. Shown are two-dimensional plots of the results of multi-dimensional scaling (MDS) analyses conducted for neurons in three color patches. Responses to each color condition were averaged across all mammal images (humans faces, monkey faces, and mammal bodies; these were selected because color tuning was most consistent between these three categories across all three patches, see Supplementary Fig. 3b). Original color is indicated by a disk of mixed color. c Neural distances of each hue to its two neighboring hues, for all three patches, computed using population responses of color-selective cells. Error bars represent s.d. of 20,000 iterations of bootstrapping. Inhomogeneity was quantified by computing the ratio between the s.d. of the 8 bars and the mean of the 8 bars: 0.21 ± 0.02 for CLC; 0.12 ± 0.02 for ALC; 0.35 ± 0.02 for AMC (p < 0.001 between CLC and AMC; p < 0.001 between ALC and AMC; p = 0.0103 between CLC and ALC, 20000 iterations of bootstrapping, see Methods). d Population similarity matrices of 10 color conditions in three color patches. A 10×10 matrix of correlation coefficients was computed between responses of all color-selective neurons averaged across objects. e For five different types of objects: grapes, watermelon, birds, gratings, and rubik’s cube, the number of AMC cells preferring each of the eight hues was counted. In all five cases, the distribution was significantly different from homogeneity (chi-square test: p < 0.001; χ²(7) = 26.3, 28.6, 31.0, 38.6 and 28.4, respectively)