Figure 5.

Responses to chromatic cues. We found three chromatic response types. A, Broad-band chromatic selectivity, where the neuron responded similarly to all colors and color combinations regardless of color. B, Narrow-band chromatic selectivity, where the neuron responded to one or two of the colors, but not all three. C, Chromatic opponency, where the responses to one color alter the response to another color. In this case, the neuron responds with a phasic burst to all colors, but with tonic activity to violet and somewhat to green. When blue and violet are presented together, the tonic activity is inhibited (gray arrows), but not when green and violet are presented together (black arrows). In all cases, black bars signify duration of the light flash. D, The percentage of chromatic response types among the responsive neurons in the layers. The layer 5–6 neurons have the highest percentage of color-sensitive neurons (narrow-band and color opponent), whereas most of the layer 1–4 and layer 1–6 neurons are mostly broad-band chromatically selective.