Color discrimination and appearance of short-duration, equal-luminance monochromatic lights

Wavelength-discrimination thresholds were measured with stimulus durations of 8, 500, and 2000 msec for test wavelengths of 420 to 630 nm at equal luminance of 100 Td. With the short duration of 8 msec, the discrimination thresholds increased for most wavelengths, but they decreased for the wavelengths near 460 nm. This short-duration wavelength-discrimination function was found to be quite different in shape from that at 2000 msec but similar to one at a low-luminance level of 2.5 Td at 500 msec. Hue, saturation, and brightness of short-duration monochromatic stimuli were also estimated by a color-naming procedure. Changes in color appearance produced by a short stimulus duration were consistent with the tendency that was characterized as tritanopic in previous studies. However, the present results on color discrimination do not necessarily support this tritanopic effect. A possible explanation is discussed.