The human electroretinogram (ERG) was elicited by an abrupt replacement of a chromatic adaptation stimulus with a long duration test stimulus. It was found that the relative spectral sensitivity of the ERG was strongly dependent upon the color and luminance of the adaptation stimulus with adaptation to a particular color lowering sensitivity to the same part of the spectrum. Clear-cut responses were produced by test luminances below an adaptation luminance only when the two were far apart in the spectrum. Analysis of the data gave definite evidence for two spectral processes with maxima near 500 and 620 mµ. There was evidence for other possible processes in the green and blue but their maxima were not well defined.
WILLIAM R. BIERSDORF and JOHN C. ARMINGTON, "Response of the Human Eye to Sudden Changes in the Wavelength of Stimulation," J. Opt. Soc. Am. 47, 208-215 (1957)