The Role of Monocular Dominance in Rivalry Onset Bias
56.503, Tuesday, 20-May, 2:45 pm - 6:45 pm, Pavilion
Jody Stanley1, Jason Forte1, Alexander Maier2, Olivia Carter1; 1Melbourne School of Psychological Science, University of Melbourne, 2Department of Psychology, College of Arts and Sciences, Vanderbilt University
When an observer is presented with dissimilar images to the right and left eye, the images will alternate every few seconds in a phenomenon known as binocular rivalry. Recent research has suggested that at the initial ‘onset’ period of rivalry there is typically a bias towards one image, which varies between individuals and across the visual field, and does not appear to be related to average dominance in sustained viewing. To further characterize the role that monocular dominance plays in the onset bias, 4 trained observers were presented with a small 0.75 degree patch of orthogonal achromatic gratings at the fovea and at 24 locations, sampling the region within 1.5 degrees eccentricity from the fovea. Gratings were presented for 1 second with 20 trials in each location. Gratings were also presented twice in every location for 1 minute to compare any onset bias with average dominance over sustained viewing. Results reveal individual differences in the contribution of eye dominance to the onset bias, with individuals displaying degrees of either right eye dominance or temporal hemifield dominance. When compared with sustained viewing, 3 out of 4 observers showed correlations between onset biases and biases in average dominance. These results demonstrate that monocular dominance plays a significant role in determining dominance at the onset of rivalry, though there are individual differences in the pattern of bias across the visual field. Monocular dominance can also affect dominance in ongoing rivalry in a way that correlates with the onset bias; however, this does not seem to be the case for all observers, suggesting that the neural mechanisms underlying onset and sustained rivalry may be distinct. In addition, some initial data assessing the relationship between onset bias and the stabilization seen with intermittent presentation will also be discussed.