Purchase this article with an account.
PD Monnier, SK Shevell; Detecting A Chromatic Change In A Moving Object . Invest. Ophthalmol. Vis. Sci. 2002;43(13):3989.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose:The dependence of motion on chromatic neural processing has been studied extensively by measuring motion performance under various isoluminant conditions. In the present study, the dependence of chromatic detection on motion was investigated by measuring the effect of motion on detecting a chromatic change. Methods:Detection thresholds were measured for a chromatic change that occurred while a small disk was moving at various speeds. Two temporal sequences of stimuli were tested: In the coherent motion condition, the disk appeared to move smoothly along a curved path equidistant from a fixation point. In the random condition, the disk moved pseudo-randomly in the display. In the luminance increment experiment, the disk was at the same chromaticity as the background but higher in luminance. In the isoluminant experiment, the disk differed from the background in chromaticity but not in luminance. The color change occurred along the L/(L+M) direction, corresponding to a reddish shift in appearance. Results:In the luminance experiment, the speed and type of motion had NO effect on detection thresholds. In the isoluminance experiment, detection thresholds were elevated compared to thresholds in the luminance condition. In the isoluminant case, thresholds decreased with speed. At low speeds, thresholds for the random condition were lower than for coherent motion, though the difference vanished at higher speeds. Conclusion:The lack of an effect of speed and type of motion in the luminance condition indicates motion did not facilitate or inhibit detection of the color change. In the isoluminant condition, motion facilitated detection of the chromatic change. The difference between random and coherent motion might be due to a differential reduction in spatial uncertainty or a potential difference in spatio-temporal masking between the two conditions.
This PDF is available to Subscribers Only