Schematic diagrams of stimulus configurations and task procedure.
(a) Illustration of dichoptic stimulus presentation; (b) Illustration of two stimulus configurations. In the positive configuration, the phase of the grating in the weak eye was shifted by θ/2 ( = 45°) from the midline while the phase in the strong eye was shifted by -θ/2. In the negative configuration, the phase-shift was reversed; (c) An example of the perceived phase (θ′) versus interocular contrast ratio δ. The perceived phase was measured as a function of interocular contrast ratio. The resulting data were fitted with the attenuation model  to compute effective contrast ratio. The black solid line is the best fit of the model. The dotted arrow line (magenta) indicates the estimated effective contrast ratio for this normally-sighted subject.