Supplementary Material for Attention Model of Binocular Rivalry

Abstract

When the corresponding retinal locations in the two eyes are presented with in-compatible images, a stable percept gives way to perceptual alternations in which the two images compete for perceptual dominance. As perceptual experi-ence evolves dynamically under constant external inputs, binocular rivalry has been used for studying intrinsic cortical computations, and for understanding how the brain regulates competing inputs. Converging behavioral and EEG results have shown that binocular rivalry and attention are intertwined: Binocular rivalry ceases when attention is diverted away from the rivalry stimuli. In addition, the competing image in one eye suppresses the target in the other eye through a pattern of gain changes similar to those induced by attention. These results re-quire a revision of the current computational theories of binocular rivalry, in which the role of attention is ignored. Here, we provide a novel computational model of binocular rivalry. In the model, competition between two images in rivalry is driv-en by both attentional modulation and mutual inhibition, which have distinct se-lectivity (feature vs. eye-of-origin) and dynamics (relatively-slow vs. relatively-fast). The proposed model is the first to explain a wide range of phenomena re-ported in rivalry, including the three hallmarks: (I) Binocular rivalry requires atten-tion; (II) Various perceptual states emerge when the two images are swapped between the eyes multiple times per second; (III) The dominance duration as a function of input strength follows Levelt’s propositions. With a bifurcation analy-sis, we identified the parameter space in which the model’s behavior was con-sistent with experimental results.