Malkoc Gokhan, Kingdom Frederick A A
Department of Psychology, Dogus University, Zeamet Sok. No. 21, Acibadem, Kadikoy, Istanbul, Turkey.
Vision Res. 2012 Jun 1;62:75-83. doi: 10.1016/j.visres.2012.03.018. Epub 2012 Apr 2.
We have investigated the properties of binocular color vision using a new measure: the Dichoptic Color Difference Threshold (DCDT). The DCDT is the smallest detectable difference in color between two dichoptically superimposed stimuli. DCDTs differ from conventional measures of binocular rivalry in that they are performance--not appearance-based. The dependency of DCDTs on (a) color direction and (b) color contrast was measured. The colors (chromaticities) of the stimuli were defined according to a scaled version of the MacLeod-Boynton color space, and the luminance and color contrasts of the stimulus pairs were equated using a matching procedure. DCDTs were measured using a forced-choice procedure in which subjects had to chose which of two stimuli had a between-eye-difference in color. DCDTs ranged from 9° to 22° of color angle depending on color direction. DCDTs were lower than binocular rivalry thresholds but higher than thresholds for discriminating the color pairs when placed side-by-side. There were no minima at either the cardinal color or unique hues directions, suggesting that DCDTs are not mediated by these mechanisms. DCDTs were however positively correlated with the measured perceived color difference between the color pairs when placed side-by-side.
我们使用一种新方法——双眼分视颜色差异阈值（DCDT），研究了双眼颜色视觉的特性。DCDT是两个双眼分视叠加刺激之间可检测到的最小颜色差异。DCDT与双眼竞争的传统测量方法不同，因为它们基于表现而非外观。我们测量了DCDT对（a）颜色方向和（b）颜色对比度的依赖性。刺激的颜色（色度）根据麦克劳德 - 博因顿颜色空间的缩放版本定义，并且使用匹配程序使刺激对的亮度和颜色对比度相等。DCDT使用强制选择程序进行测量，在该程序中，受试者必须选择两个刺激中哪一个在两眼之间存在颜色差异。根据颜色方向，DCDT的颜色角度范围为9°至22°。DCDT低于双眼竞争阈值，但高于将颜色对并排放置时区分颜色对的阈值。在主要颜色或独特色调方向上均没有最小值，这表明DCDT不是由这些机制介导的。然而，当颜色对并排放置时，DCDT与测量的颜色对之间的感知颜色差异呈正相关。
