A PHYSICAL BASIS FOR THE CHROMATIC S POTENTIALS IN COLOR VISION

Abstract— The photoelectric response S (photoconduction and the photovoltaic effect) of a β-carotene cell are shown to replicate in detail the photoelectric color responses of animal retina — the chromatic S potentials, In both, short-wavelength light generates a negative current flow with relatively fast time constants; long-wavelength light generates a positive current flow with longer time constants; intermediate wavelength lights generate currents which are superpositions of these two currents and exhibit on/off peaks. A slight modification of the 'primitive theory of the electroretinogram' previously suggested, incorporates these color responses in the theory. The correlation between the physical detector and the retinal receptor unit suggested by this theory can explain the facts that agents which enhance the glial membrane potential increase the red response and decrease the blue response of the chromatic 5 potentials. The response changes due to adaptation can also be explained by the theory.