Increment-threshold spectral sensitivity was measured on rhesus monkeys. Homogeneous 20° backgrounds were used, illuminated by a planckian radiator (2854°K white) producing 3000 trolands retinal illuminance and also that white plus an intense spectral-line field of 10 000 td. The white background produced sensitivity functions with pronounced peaks at approximately 450 nm, 535 nm, and 610 nm. Adding intense red, green, or blue light to the background served to eliminate or nearly eliminate the peak in the spectral region nearest the spectral-background component. For the red and green lines, the peaks in the other parts of the spectrum were only slightly reduced. For the blue line, the entire function was altered, with greater reduction of sensitivity through the entire visible spectrum, resulting in a function with a single broad peak in the 570–90 nm region. The results are discussed in terms of the summation of component receptor mechanisms, the possible implications for a fourth linked red-plus-green mechanism to account for the blue adaptation results and a comparison is made with results from electrophysiological studies.
H. G. SPERLING, N. A. SIDLEY, W. S. DOCKENS, and C. L. JOLLIFFE, "Increment-Threshold Spectral Sensitivity of the Rhesus Monkey as a Function of the Spectral Composition of the Background Field," J. Opt. Soc. Am. 58, 263-268 (1968)