Abstract
Electroretinograms (ERGs) elicited by transient, square-wave L-and M-cone isolating stimuli were recorded from human trichromatic (n = 19) and dichromatic (n = 4) observers. The stimuli were generated on a four primary LED stimulator and were equated in terms of cone modulation (cone contrast = 0.11) and retinal illuminance (12,000 trolands). L-and M-cone isolated ERGs had waveforms similar to those observed for luminance responses. However, M-cone ERGs exhibited a phase reversal in their responses to onset and offset stimuli relative to the L-cone responses. This on-off response reversal was observed in trichromats but not dichromats. Simultaneous counterphase and inphase combinations of L-and M-cone isolating stimuli generated responses that reflected chromatic and luminance processing, respectively. We conclude that L-and M-cone specific ERGs provide a measure of how photoreceptors contribute to postreceptoral mechanisms. (c) 2014 Optical Society of America