Electroretinographic responses to photoreceptor specific sine wave modulation.

Electroretinographic responses to cone and rod isolating stimuli and to simultaneous L- and M-cone modulation were measured at different temporal frequencies between 2 and 60 Hz and at two mean luminances using a four primary stimulator. The responses driven by each photoreceptor type had distinct characteristics. The responses to stimuli containing L- and/or M-cone stimulation indicated the presence of two underlying mechanisms that were active in distinct frequency regions. Between 2 and 12 Hz, the responses displayed properties that were reminiscent of the L-M-cone opponent system. At higher temporal frequencies, the electroretinograms were more determined by the luminance content in the stimuli.