Orientation specific colour adaptation at a binocular site

Abstract

MCCOLLOUGH¹ found that after alternate viewing of vertically oriented red gratings and horizontally oriented blue gratings, achromatic gratings appear tinted blue when oriented vertically and pink when oriented horizontally. This indicates the existence of colour specific edge detectors in the visual system. Further, since interocular transfer of the effect was not possible, McCollough concluded that no binocular cells are involved in this type of adaptation. This view has been supported by many investigators^2–5 who used different paradigms. But their failure to illustrate orientation-contingent colour adaptation at a binocular locus may be attributable to the fact that most of their experimental situations, like McCollough's, did not provide the ideal stimulus for binocular neurones, which respond best, showing “binocular synergy”, only when the stimulus is simultaneously presented to both eyes^6–9. I have attempted optimal excitation of the binocular cells by alternately presenting red vertical and blue horizontal gratings to both eyes and isolating adaptation of binocular neurones by cancelling monocular adaptation with presentation of a pair of complementary gratings (blue vertical and red horizontal) to each eye separately for an equal length of time. The results of this procedure show that adaptation does involve binocular neurones.