Kevin Dieter, PhD and the lab of Dr. Randolph Blake receive a prestigious National Eye Institute NRSA grant

Project title: Psychophysical and neural correlates of eye dominance in human vision

Advisor: Randolph Blake

Consultants: Frank Tong, Psychological Sciences and Sean Donahue, Ophthalmology, Pediatrics, Neurology

Summary: While we effortlessly see a single, unitary visual world, it is easy to forget that this experience arises from two separate (left and right eye) views of the environment. The transformation from distinct monocular views to stable binocular single vision is the manifestation of important neural processes that give rise to significant improvements in visual perception, including stereoscopic depth perception and binocular contrast summation. In cases of sensory eye dominance (SED), a condition where one of the two eyes contributes more strongly to the binocular percept than the other, these gains can be muted or, in extreme instances, completely thwarted. Under these conditions, vision with two eyes is no better than with one, and in some instances is worse owing to monocular competition.

This project builds on the interesting recent discovery that SED may vary idiosyncratically throughout the visual field, potentially due to the local nature of visual mechanisms involved in combining neural signals from the two eyes. First, I will investigate how patterns of SED vary across visual field locations, and will test for influences of regional SED on binocular function. Then, I will apply functional magnetic resonance imaging (fMRI) to investigate how neural activity underlying visual field regions with strong SED imbalance differ from those sub-serving regions where both eyes contribute equally. Results from the proposed research can lead to a deeper understanding of typical and atypical binocular visual function, potentially leading to translational applications in the diagnosis and treatment of binocular visual disorders.