Indexing Sensory Eye Dominance

Sensory eye dominance occurs when one eye’s input is weighted more preferably to that of the other. Currently, though there are different tests that are commonly used to index sensory eye dominance, they lack agreement in terms of their classification of the dominant eye. To systematically examine how sensory eye dominance might be influenced by stimulus and task demands, we designed tasks that we classified into two different categories: rivalrous tasks, which entail binocular competition and the eventual selection of one eye’s data over the other; and integrative tasks, which allow for the combination of the two eyes’ inputs in order to solve the task. For each category, we included tasks using a variety of different features. Specifically, for rivalrous tasks, we included letters with opposing polarity, opposite motion gratings, and masked oriented gratings of varying contrasts. For the integrative tasks, we included motion, glass pattern orientation, and gratings with phase shifts. Separately, we also included a depth perception task, which served as a test for one functional implication of eye dominance: stereovision. We found that sensory eye dominance classifications differ among tasks. When comparing across the categories of tasks, integrative tasks produced higher classification consistency than rivalrous tasks (e.g., the dominant eye classified by using integrative tasks is more likely to be the same eye). In terms of stereovision, we found no clear correlation between the magnitude of the sensory eye dominance and performance for the depth task. Our data suggest that sensory eye dominance is sensitive to task and feature demands and should therefore be indexed with caution. The apparent difference in outcomes derived from integrative- versus rivalrous-type tasks suggest they tap into independent mechanisms of sensory eye dominance.