Color-binding errors induced by modulating effects of the preceding stimulus on onset rivalry

Onset rivalry can be modulated by a preceding stimulus with features similar to rivalrous test stimuli. In this study, we used this modulating effect to investigate the integration of color and orientation during onset rivalry using equiluminant chromatic gratings. Specifically, we explored whether this modulating effect leads to a decoupling of color and orientation in chromatic gratings, resulting in a percept distinct from either of the rivalrous gratings. The results demonstrated that color-binding errors can be observed in a form where rivalrous green-gray clockwise and red-gray counterclockwise gratings yield the percept of a bichromatic, red-green grating with either clockwise or counterclockwise orientation. These errors were observed under a brief test duration (30 ms), with both monocular and binocular presentations of the preceding stimulus. The specific color and orientation combination of the preceding stimulus was not critical for inducing color-binding errors, provided it was composed of the test color and orientation. We also found a notable covariant relationship between the perception of color-binding errors and exclusive dominance, where the perceived orientation in color-binding errors generally matched that in exclusive dominance. This finding suggests that the mechanisms underlying color-binding errors may be related to, or partially overlap with, those determining exclusive dominance. These errors can be explained by the decoupling of color and orientation in the representation of the suppressed grating, with the color binding to the dominant grating, resulting in an erroneously perceived bichromatic grating.