Abstract
Purpose. Previous studies have reported the dominance of a sharp image when it competes during binocular rivalry (BR) with a blurred (low-pass filtered) version of itself [e.g., Chai, Papathomas, Zhuang, Alais, VSS 2009]. In the current study we continued our efforts to mimic “monovision” correction (two drastically different focal distances for near and far in the two eyes). We investigated interocular grouping of sharp and blurred components of an image under “patchwork” BR [e.g., Kovacs, Papathomas, Feher, Yang, PNAS 1996] that is expected under monovision correction. Methods. Each eye had a 2x3 checkerboard pattern of alternating sharp and blurred patches with the complementary pattern in the other eye. Four types of conditions were compared. (1) Grayscale images with steady fixation (2) Grayscale images with the fixation mark changing position every 2 s. (3) Color condition: Sharp/blurred patches were red/green or vice versa. (4) Control condition for (3): Color patchworks either all-sharp or all-blurred images. Task was to press different buttons to report dominance of sharp/blurred features in (1) and (2) and of red/green in (3) and (4). Results. Strong interocular grouping was observed in all four conditions: 66%,67%,82%,61% in conditions 1, 2, 3, 4. Predominance of sharp patches was always larger versus blurred patches (45%, 41%, 53% versus 21%, 26%, 30% in conditions 1, 2, 3, respectively). Color enhanced the interocular grouping for both sharp and blurred features, as compared with grayscale conditions. Results were not significantly different between conditions 1 and 2. Conclusions. These results corroborate and extend earlier findings for the dominance of sharp features. They help explain how monovision can function, even when the gaze changes, as indicated by condition 2. The well-documented ability of color for interocular grouping (condition 4) explains the enhanced interocular grouping of condition 3 over 1.
Laboratory of Vision Research, Center for Cognitive Science IGERT on Perceptual Science.