Opponent-colors responses in the visually evoked potential in man.

Abstract The responses of visually evoked cortical potential (VECP) of three observers with normal-color vision were measured for 10 different spectral stimuli ranging from 400 to 700 nm with the equal retinal illuminance of 300 td. These responses were analyzed by use of the principal component analysis, and the results obtained are as follows: (1) Opponent-colors responses were found for two of the three observers which were similar to those derived by Jameson-Hurvich on the basis of psychophysical methods. (2) The VECP responses for another observer were almost independent of the different spectral stimuli applied. This was interpreted as a noncolor-coding observer, as shown by Shipley. (3) The same analysis was applied to the VECP responses measured by Shipleyet al. (1968). Though the waveforms are significantly different from those by the present authors, similar opponent-colors responses were also derived.