Two temporal phases, brightness-dependent and -independent, in the chromatic response elicited by a briefly-flashed monochromatic light: a preliminary report.

The strength of chromatic response elicited by a briefly-flashed monochromatic light, which varied in its exposure duration, was measured with the "transient cancellation method" in Experiment 1. It was found that the chromatic response of a test color depended on brightness of the test field, up to the exposures of 100-200 msec. But it began to decrease, independent of brightness of the field, at the longer durations. The above results were confirmed by Experiment 2, in which the perceived saturation of a colored light was estimated with the two alternative forced choice method. Those results were tentatively interpreted as indicating the two kinds of chromatic responses presumably originating at the different stages in the visual system. Some other psychophysical dada on color vision were briefly referred to in relation to the present results.