Temporal Color Perception

Color perception has been widely studied and well modeled with respect to combining visible electromagnetic frequencies, yet new technology provides the means to better explore and test novel temporal frequency characteristics of color perception. Experiment 1 tests how reliably participants categorize static spectral rainbow colors, which can be a useful tool for efficiently identifying those with functional dichromacy, trichromacy, and tetrachromacy. The findings confirm that all individuals discern the four principal opponent process colors, red, yellow, green, and blue, with normal and potential tetrachromats seeing more distinct colors than color blind individuals. Experiment 2 tests the moving flicker fusion rate of the central electromagnetic frequencies within each color category found in Experiment 1 as a test of the Where system. It then compares this to the maximum temporal processing rate for discriminating direction of hue change with colors displayed serially as a test of the What system. The findings confirm respective processing thresholds of about 20 Hz for Where and 2-7 Hz for What processing systems. Experiment 3 tests conditions that optimize false colors based on the spinning Benham’s Top illusion. Findings indicate the same four principal colors emerge as in Experiment 1, but at low saturation levels for trichromats that diminish further for dichromats. Taken together, the three experiments provide an overview of the common categorical boundaries and temporal processing limits of human color vision.