Red--green and blue--yellow mechanisms are matched in sensitivity for temporal and spatial modulation.
The spatial and temporal properties of human colour vision are examined using isoluminant, red--green and blue--yellow tritanopic gratings. Chromatic sensitivity is found to be low-pass as a function of both spatial and temporal frequency along all the chromatic axes investigated, including the tritanopic confusion lines employed to examine the properties of the S-cone driven mechanism. Comparison of sensitivity to on-off and contrast reversing stimuli indicates that transient mechanisms contribute to the detection of red--green patterns but that the detection of S-cone specific patterns is governed by sustained mechanisms. By compensating for transient contributions to red--green sensitivity, it is shown that sensitivity of chromatic mechanisms dominated by L- and M-cone input are closely matched to those with S-cone input.
McKeefry
D J
DJ
School of Biomedical Sciences, University of Ulster, Cromore Road, Coleraine, BT52 1SA, UK.
Murray
I J
IJ
Kulikowski
J J
JJ
D003118:Color Perception / Q000502:physiology*; D015350:Contrast Sensitivity / Q000502:physiology*; D006801:Humans; D011601:Psychophysics; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*