Abstract
Cone contrast detection thresholds were measured for gratings modulated spatially and temporally about a white field using odd symmetric Gabors. A particular pairing of the spatial and temporal frequency carriers was used in each experimental session. Thresholds were measured using randomly interleaved staircases; for one set of stimuli only the M-cone input was varied. For a second set only the L-cone input was varied.
For targets of low spatial and low temporal frequency L- and M- cone sensitivities were approximately equal. The ratio of L-cone to M-cone sensitivity increased when temporal frequency was raised (confirming previous findings) and when spatial frequency was raised (a novel finding). To some degree the effects of spatial and temporal frequency are additive but the interaction is complex.
Supported by NEI grant EY06638