Abstract
Sensory eye dominance (SED) refers to one eye having a competitive advantage over the fellow eye when viewing a pair of binocular rivalry stimuli with equal strength (Ooi & He, 2001). SED is largely related to the interocular inhibitory mechanism underlying various binocular percepts. To date, we have only measured the global SED using a binocular rivalry display that stimulates large visual field coverage. We now measured the local SED at various retinal locations (SED Perimetry) using a binocular rivalry method similar to that used in the global SED and a QUEST procedure. We selected 17 different retinal locations that included one at the fovea, eight at 2deg and eight at 4deg eccentricity. At each test location, we measured the SED by presenting a binocular rivalry display (vertical vs. horizontal grating) on an 11×11deg gray background (35 cd/m2) for 0.5 sec. At the fovea the spatial frequency and size of the rivalry grating discs were 5cpd and 0.75deg, respectively; and at the peripheral locations the discs were scaled according to the retinal eccentricity. Furthermore, at each test location we measured: (i) The right and left eye's contrast sensitivity using monocular gratings having the same parameters as the binocular rivalry display; (ii) Stereo threshold of a front disc defined by random-dots; (iii) Choice reaction time to the onset of the random-dots defined disc with either 6 min front or back binocular disparity. We found that: (1) both the sign (right or left eye) and magnitude of the local SED vary with test location, indicating that the local SED is retinal location specific; (2) the local SED cannot be attributed to the difference in monocular contrast sensitivity; (3) both the stereo threshold and reaction time tend to increase with the magnitude of the local SED, suggesting that SED can impede stereo processing.
National Institutes of Health (EY015804).