A reevaluation of angle-contingent color aftereffects

Abstract

It has been argued that adaptation to a series of angles with vertices pointing up and illuminated in one color, and to angles with vertices pointing down and illuminated in the opponent color, results in color aftereffects that are contingent on angle direction. In the present paper, using a number of test figures, we demonstrate that adaptation to these ascending/descending angles results in color aftereffects that can be accounted for in terms of spatially localized, orientation-color pairings. In the light of our results, we suggest that previous inferences concerning angle-contingent color aftereffects should be reconsidered.Contingent aftereffects, originally reported by McCollough (1965), are of theoretical interest, not only because of their remarkable persistence over time, but also as a possible methodology for exploring feature-detector models of human visual perception. McCollough (1965) described an orientationcontingent color aftereffect. During a 3-min adaptation period, her subjects inspected two figures that alternated every few seconds. Under one condition, one adaptation figure consisted of black vertical bars illuminated by orange light and the other consisted of black horizontal bars illuminated by blue light. During the test phase, the subjects viewed an achromatic figure, half of which consisted of black vertical bars on a white background and the other half, of black horizontal bars on a white background. The subjects reported colored aftereffects which were contingent on line orientation. For the above condition, the white background of the vertical bars appeared bluish and the white background of the horizontal bars appeared orangish. This orientationcontingent color aftereffect was interpreted by McCollough (1965) as psychophysical evidence for neural units that are both color-and orientationspecific. She argued that the aftereffect could be understood in terms of color adaptation of orientationspecific edge detectors.Since the original report by McCollough (1965), color aftereffects contingent on movement direction (e.g

Orientation-contingent color aftereffects: Retinal specificity

“…concluded that the color aftereffects they obtained were orientation contingent rather than angle contingent, and they argued that these orientation·contingent color aftereffects were retinally specific. Additional data in support of the Hayman and Allan (1980) conclusion are reported. These data point to the important role of eye fixations and eye movements on contingent color aftereffects.…”

Color aftereffect contingent on text

“…In fact, there has even been debate about aftereffects contingent on features such as curvature and angle. Although some investigators claim to have found color aftereffects contingent on curvature (Cavill & Robinson, 1976;Riggs, 1973Riggs, , 1974White & Riggs, 1974) or on angle (White & Riggs, 1974), others have argued that these aftereffects are really contingent on orientation (Allan & Hayman, 1982;Crassini & Over, 1975;Hayman & Allan, 1980;MacKay & MacKay, 1974;Sigel & Nachmias, 1975;Stromeyer, 1974).…”

Text-contingent color aftereffects: A reexamination

“…Others, however, have not been able to obtain effects under similar induction conditions in which the pattern moved relative to the retina (Mackay & MacKay, 1974;Sigel & Nachmias, 1975;Stromeyer, 1974). Furthermore, Hayman and Allan (1980) found that there were changes in the hue reported as a result of shifts in the locus of fixation on test figures and that these changes were those that were expected on the basis ofspatially localized aftereffects. On balance, it appears that chevron-like patterns produce highly localized orientation-contingent aftereffects.…”

“…White and Riggs (1974;see also Riggs, 1973) have proposed that such patterns contain angles and adapt mechanisms that are sensitive to the direction of departure from a straight line. Many other results suggest, however, that induction with angled or curved line patterns can be accounted for in terms of adaptation of mechanisms sensitive to line orientation and retinal position (e.g., Crassini & Over, 1975;Hayman & Allan, 1980;Sigel & Nachmias, 1975). White and Riggs argued that the color aftereffects cannot be due to local color and orientation contingencies, because they obtained color aftereffects when subjects slowly scanned the patterns.…”