Cone weights for the two cone-opponent systems in peripheral vision and asymmetries of cone contrast sensitivity.
In understanding the basis of the changes in human color vision across eccentricity, one key piece of information remains unknown, whether the relative cone weights of the two cone opponent mechanisms vary. Here we measure detection threshold contours within three planes in a 3-dimensional cone contrast space to reveal the L, M and S-cone weights to the two cone opponent mechanisms, L/M and S/(L+M). We find these remain constant across eccentricity suggesting the underlying structures of the cone opponent mechanisms are invariant. The contrast sensitivities of two poles of the S-cone opponent mechanism also remain symmetrical, whereas small asymmetries develop in L/M opponency from about 15 degrees.
Sakurai
Masato
M
McGill Vision Research, Department of Ophthalmology, McGill University, Montreal, Que., Canada H3A 1A1.
Mullen
Kathy T
KT
D003118:Color Perception / Q000502:physiology*; D015350:Contrast Sensitivity / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation / Q000379:methods; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*; D012684:Sensory Thresholds / Q000502:physiology; D014794:Visual Fields / Q000502:physiology