by University of Pennsylvania (a) Signals from the L/M (hereafter “L”) and S cones are combined and contrasted to create two postretinal channels that signal luminance and chrominance. (b) Spectral sensitivities of the canine photoreceptors. (c) Stimulus spectra used to target particular photoreceptor combinations. Each stimulus modulated between a stimulating (red) and suppressing (black) spectrum around...
