Properties of hue channels examined using a dichoptic adaptation technique

We used a hue scaling technique (Gordon and Abramov, 1988) to describe the color appearance of monocular stimuli before and after chromatic adaptation to the other eye. Stimuli were 0.5-s equiluminant monochromatic flashes varying in wavelength between 440 and 660 nm. The adapting stimulus was turned off shortly before each test flash. Four adapting conditions were used corresponding approximately to the unique hues. As found in previous studies on the binocular properties of chromatic mechanisms (Shevell, Humanski et al.), the effects of this type of adaptation are complicated. Some of our effects include the following. The maximal adapting effects do not necessarily occur at the same wavelengths as those of the adapting stimuli. Regardless of the adapting hues, the largest effects of adaptation are seen in the green-yellow parts of the test spectrum. The adapting stimulus contributes its complement to the test eye (e.g., red adaptation cancels some of the redness in the test eye and enhances greenness). In the past, we have described tritanopic blue (blue seen in tritanopic conditions at wavelengths longer than 500 nm). In this experiment, this condition can be seen when the opposite eye is adapted to yellow. There is an increase in the appearance of blue at wavelengths >500 nm.