Flicker VEPs reflecting multiple rod and cone pathways.
In an attempt to determine whether the relative contributions of magno-mediated and parvo-mediated inputs to the cortex are significantly altered in the transition from cone to rod vision, VEPs were recorded at different luminance levels (photopic to scotopic) for 2Hz square-wave, isochromatic flicker. The VEP mass response appears capable of reflecting major parvo-mediated contributions even at luminance levels for which responses from individual cells in the parvocellular pathway are reported to be weak. Our findings suggest that parvo-mediated responses are the dominant source of high-contrast isochromatic flicker VEPs at all light levels.
Rudvin
Inger
I
Institute of Physics, Section of Biophysics, Norwegian University of Science and Technology, Trondheim, Norway. rudvin@phys.ntnu.no
Valberg
Arne
A
D000293:Adolescent; D000328:Adult; D002648:Child; D015350:Contrast Sensitivity / Q000502:physiology; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation / Q000379:methods; D011601:Psychophysics; D011930:Reaction Time / Q000502:physiology; D015203:Reproducibility of Results; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology; D014795:Visual Pathways / Q000502:physiology