The hypnotic induction of hallucinatory color vision followed by pseudo-negative after-images.

Abstract

Four deeply hypnotized subjects, in response to appropriate suggestions upon the exhibition of sheets of white paper, were able to hallucinate repeatedly the colors red, green, blue and yellow. Each instance of such color hallucination was immediately and invariably succeeded by the spontaneous hallucination of the complementary color in the form of a negative after-image, such as occurs in actual color vision. Direct questioning and word association tests before and after the expt. disclosed no tendency to associate directly the complementary colors. Comment is made on the associational and neuro- and psycho-physiological processes involved, and the significance of the results is considered to be their evidential value of the importance of cortical processes in color vision.