Incremental and decremental L- and M-cone-driven ERG responses: I. Square-wave pulse stimulation.
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.
Declan
D
McKeefry
Jan
J
Kremers
Deepika
D
Kommanapalli
Naveen K
NK
Challa
Ian J
IJ
Murray
John
J
Maguire
Neil R A
NR
Parry
D000293:Adolescent; D000328:Adult; D002648:Child; D003118:Color Perception / Q000502:physiology*; D004596:Electroretinography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation; D012160:Retina / Q000502:physiology*; D017949:Retinal Cone Photoreceptor Cells / Q000166:cytology; D055815:Young Adult