Abstract
Temporarily (120 mins) patching one eye subsequently increases the amount of time spent consciously perceiving the deprived eye's image during binocular rivalry. A recent MRS investigation [Lunghi et. al, 2015] suggests that a reduction in cortical inhibition of the deprived eye may be responsible for the patching-induced shift in ocular dominance. In the present study we investigated whether the occurrence of mixed percepts in binocular rivalry (percepts that require integrated information from both eyes) changes as a result of monocular deprivation. Participants viewed orthogonal ( +/- 45° ) sinusoidal gratings presented individually to each eye and completed a 5AFC task over the course of a 3-minute block where they indicated whether they were seeing one of the following: (1) an exclusively left-tilted grating, (2) a mostly left-tilted-grating (mixed, left-dominant), (3) a balanced fusion of the two gratings, (4) a mostly right-tilted-grating (mixed, right-dominant), or (5) an exclusively right-tilted grating. Total durations and mean durations were obtained for each percept from a 9-minute baseline session and a 6-minute session after 2 hours of deprivation. Post/baseline ratios (log2) were calculated and used for analysis in a 2-way (time x percept) repeated measures ANOVA. Preliminary data indicate significant time x percept interactions for both total durations and mean durations (Fs = 41, 7; ps < 0.05). Pairwise comparisons show significant patching–induced increases in the proportion and mean duration of mixed percepts dominated by the patched eye (t= -2.8, - 2.6; ps < 0.05) and significant decreases in the proportion of exclusive percepts from the unpatched eye (t = 3.5; p < 0.05). These findings suggest that the ocular dominance shift produced by short-term monocular deprivation is driven by an increase in mixed (binocular) percepts favoring the patched eye, and by a decrease in exclusive (monocular) percepts from the unpatched eye.
Meeting abstract presented at VSS 2018