title: Unifying account of visual motion and position perception.
abstract: Despite growing evidence for perceptual interactions between motion and position, no unifying framework exists to account for these two key features of our visual experience. We show that percepts of both object position and motion derive from a common object-tracking system--a system that optimally integrates sensory signals with a realistic model of motion dynamics, effectively inferring their generative causes. The object-tracking model provides an excellent fit to both position and motion judgments in simple stimuli. With no changes in model parameters, the same model also accounts for subjects' novel illusory percepts in more complex moving stimuli. The resulting framework is characterized by a strong bidirectional coupling between position and motion estimates and provides a rational, unifying account of a number of motion and position phenomena that are currently thought to arise from independent mechanisms. This includes motion-induced shifts in perceived position, perceptual slow-speed biases, slowing of motions shown in visual periphery, and the well-known curveball illusion. These results reveal that motion perception cannot be isolated from position signals. Even in the simplest displays with no changes in object position, our perception is driven by the output of an object-tracking system that rationally infers different generative causes of motion signals. Taken together, we show that object tracking plays a fundamental role in perception of visual motion and position.
authors.affiliation: Center for Visual Science and Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY 14627;
authors.forename: Oh-Sang
authors.initials: OS
authors.lastname: Kwon
authors.affiliation: Center for Visual Science and Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY 14627; Department of Ophthalmology, University of Rochester School of Medicine, Rochester, NY 14642 duje@cvs.rochester.edu.
authors.forename: Duje
authors.initials: D
authors.lastname: Tadin
authors.affiliation: Center for Visual Science and Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY 14627;
authors.forename: David C
authors.initials: DC
authors.lastname: Knill
mesh_terms: D006801:Humans; D008954:Models, Biological; D009039:Motion Perception; D014796:Visual Perception
keywords: Kalman filter; causal inference; motion-induced position shift; object tracking; visual motion perception