A Study of Binocular Color Mixture

Using an apparatus which presents simultaneously the components for binocular color mixing to each eye and an additive, comparison mixture of the components to both eyes, an investigation was made of the effects of stimulus size, exposure time, and surround on the frequency with which the observers reported matching binocular mixtures. A comparison of binocular with additive mixtures as a function of (1) their relative total luminances using equal binocular components and (2) variable binocular composition with constant total luminance was also carried out. A brief history of work on binocular color mixture has been included. Resume—Avec un appareil qui presente simultanement les constituants d'un melange binoculaire de couleur dans chaque oeil ainsi qu'un melange additif de comparaison vu par les deux yeux, on a recherche les effets de la dimension, de la duree, et de l'environnement du stimulus sur la frequence avec laquelle les melanges binoculaires sont percus. On a aussi examine la comparaison des melanges binoculaires avec les melanges additifs en function (1) de leurs luminances relatives totales pour des constituants binoculaires egaiix et (2) de constituants binoculaires variables pour une luminance totale constante. On a inclus un bref historique du Probleme du m61ange binoculaire de couleur. Zusammenfassung—Ein Apparat, der gleichzeitig jedem Auge je eine Farbkomponente für binokulares Farbensehen und zum Vergleich eine additive Farbmischung aus beiden Komponenten anbietet, wurde dazu benutzt, um den Einfluss der Reizgrösse, der Darbietungszeit und des Umfeldes von der Häufigkeit der beobachteten binokularen Farbmischungen festzustellen. Ein Vergleich von binokularer und additiver Mischung wurde bei gleichen binokularen Komponenten und bei gleicher totaler Leuchtdichte als eine Funktion (I) der relativen totalen Leuchtdichte und (2) der variablen binokularen Komponenten ausgeführt. Vorangegangene Arbeiten über binokulare Farbmischungen werden einleitend kurz erwähnt. THE binocular mixture of colors was first reported by Haldat in 1806, and the succeeding early literature on the subject was largely concerned with the authenticity of the phenomenon. While many investigators vouched for it, a few were able to achieve only such related effects as oscillation or the dominance of one of the components (SOUTHALL, 1924). This early literature was summarized by Helmholtz and Hering, who, as was often the case, took opposite points of view on the question. From his unsuccessful attempts, Helmholtz (SOUTHALL, 1924) concluded that the alleged binocular mixtures were due to background induction, the absence of a uniocular comparison field, or the presence of afterimages. HERING (1864) believed that binocular mixture was always possible if certain precautions were taken: the colored areas should be small and the same in shape, contour differences should be minimized, the colors should be of equal brightness and not widely separate in hue; complementary colors could be mixed if they were unsaturated and dull. 1 Now at HumRRO, Ft. Rucker, Ala.