|Title||Motor ocular dominance varies with test distance but sensory ocular dominance does not|
|Author, Co-Author||Sergiu Picioreanu, Benjamin Thompson, Kristine Dalton|
Motor ocular dominance varies with test distance but sensory ocular dominance does not
Sergiu Picioreanu, Benjamin Thompson, Kristine Dalton
Purpose: We have previously found that motor ocular dominance increases with longer test distances suggesting that clinical tests of ocular dominance should take test distance into account. Here we compared the effect of test distance on quantitative measures of both motor and sensory ocular dominance.
Methods: 19 participants with normal binocular vision completed measures of motor and sensory ocular dominance and phoria at four test distances; 1m, 2m, 3m, and 4m. Test stimuli were scaled to ensure a constant visual angle across test distances. Motor dominance was measured using a sighting test that allowed for the use of a visual analogue scale to quantify the strength of dominance. Sensory dominance was measured using a dichoptic global motion task that quantified the relative weighting of each eye’s contribution to the perception of coherent motion within random dot kinematogram stimuli.
Results: The effect of test distance on ocular dominance differed significantly between the motor and sensory dominance tests (F = 7.9 p < 0.001). In agreement with our previous results, motor dominance increased in strength for longer test distances (F = 27.3, p < 0.001) and this could not be accounted for by changes in convergence demand. Test distance had no effect on sensory dominance (F = 0.1, p = 0.9). Motor and sensory dominance were positively but weakly correlated at each test distance.
Conclusion: The differential effect of test distance on motor and sensory ocular dominance suggests that these two types of ocular dominance involve at least partially distinct neural mechanisms.
|Affiliation of Co-Authors||University of Waterloo, University of Waterloo|