Spatio-temporal frequency characteristics of color-vision mechanisms*

Spatio-temporal sine-wave response functions are inferred for the red-, green-, and blue-sensitive receptor mechanisms of the visual process, by selective chromatic-adaptation experiments and Weber-law calculations. The complete spatio-temporal threshold surface for each cone mechanisms is abbreviated to four critical profiles: two contrast-sensitivity curves measured at the temporal frequencies of minimum and maximum sensitivity, and two flicker-sensitivity curves measured at the spatial frequencies of minimum and maximum sensitivity. Throughout most of the spatio-temporal frequency domain, the green sensitivity is greatest, the red is less, and the blue is least of all. The curve shapes can be qualitatively explained in terms of antagonistic interactions in the early visual pathways.