Figure 3.

The distribution of cells in LGN and V1 that are tuned to +/−15° of the cardinal vectors (0°, 90°, 180°, and 270°) versus the regions of the perceptual color vectors (10°, 125°, 220°, and 290° for red, blue, green, and yellow, respectively). It is apparent that, on average, striate cells are shifted off the LGN cardinal vectors toward the perceptual color vectors (regions indicated below the x axis). The color tuning of our LGN L/M cell population was shifted slightly from the canonical 0°-180° axis. Approximately 90% of the L/M cells were tuned to +/−15° from the −10° to 170° and the 90°-270° axes.