Flicker ERGs representing chromaticity and luminance signals.
OBJECTIVE
To test the hypothesis that electroretinograms (ERGs) reflect luminance activity when measured at high temporal frequencies and chromatic activity when measured near 12 Hz.


METHODS
The authors measured the responses to stimuli in which the output of red and green light-emitting diodes was modulated in counterphase at different ratios, varying the luminance content in the stimulus while keeping the red-green chromatic contrast and its phase constant.


RESULTS
The high temporal frequency electroretinography was determined mainly by the luminance contrast. At 12 Hz, electroretinographic response amplitudes and phases primarily reflected the red-green chromatic content of the stimulus. Control experiments, performed with a deuteranopic subject and with stimuli that silenced the rods and S-cones, excluded an explanation based on intrusion from rod- and S-cone-driven responses.


CONCLUSIONS
It now is possible to perform noninvasive measurements of basic electrophysiological properties of the luminance and chromatic pathways on a retinal level, and their disease-related changes, in human observers.
Kremers
Jan
J
Department of Ophthalmology, University Hospital Erlangen, Erlangen, Germany. jan.kremers@uk-erlangen.de
Rodrigues
Anderson Raiol
AR
Silveira
Luiz Carlos de Lima
LC
da Silva Filho
Manoel
M
D055253:Color Vision / Q000502:physiology*; D003117:Color Vision Defects / Q000503:physiopathology*; D004596:Electroretinography; D006801:Humans; D020419:Photoreceptor Cells, Vertebrate / Q000502:physiology*; D051245:Retinal Bipolar Cells / Q000502:physiology*