Binary kernels of VEPs elicited by luminance-modulated stimuli

In order to investigate the characteristics of luminance channels in the human color visual system, the binary kernel method was applied to VEPs elicited by luminance-modulated stimuli of constant chromaticity. Binary kernels of VEPs measured from normal subjects were estimated, and the relationship between the waveforms of kernels and stimuli was examined. The results showed that the waveforms of kernels were independent of the chromaticity of stimuli, and that they reflected the characteristics of the luminance channel. Since binary kernels up to the 3rd order were typical, the luminance-VEP system can be described by a 3rd-order nonlinear system. Waveforms of 1st- and 2nd order kernels depended on the mean luminance and contrast of the stimulus, and the amplitudes of 3rd-order kernels increased according to contrast.