title: Area MT encodes three-dimensional motion.
abstract: We use visual information to determine our dynamic relationship with other objects in a three-dimensional (3D) world. Despite decades of work on visual motion processing, it remains unclear how 3D directions-trajectories that include motion toward or away from the observer-are represented and processed in visual cortex. Area MT is heavily implicated in processing visual motion and depth, yet previous work has found little evidence for 3D direction sensitivity per se. Here we use a rich ensemble of binocular motion stimuli to reveal that most neurons in area MT of the anesthetized macaque encode 3D motion information. This tuning for 3D motion arises from multiple mechanisms, including different motion preferences in the two eyes and a nonlinear interaction of these signals when both eyes are stimulated. Using a novel method for functional binocular alignment, we were able to rule out contributions of static disparity tuning to the 3D motion tuning we observed. We propose that a primary function of MT is to encode 3D motion, critical for judging the movement of objects in dynamic real-world environments.
authors.affiliation: Dominick Purpura Department of Neuroscience, and thaddeus.czuba@einstein.yu.edu.
authors.forename: Thaddeus B
authors.initials: TB
authors.lastname: Czuba
authors.affiliation: Center for Perceptual Systems, Departments of Neuroscience and Psychology, The University of Texas at Austin, Austin, Texas 78712.
authors.forename: Alexander C
authors.initials: AC
authors.lastname: Huk
authors.affiliation: Center for Perceptual Systems, Psychology, The University of Texas at Austin, Austin, Texas 78712.
authors.forename: Lawrence K
authors.initials: LK
authors.lastname: Cormack
authors.affiliation: Dominick Purpura Department of Neuroscience, and Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, New York 10461, and.
authors.forename: Adam
authors.initials: A
authors.lastname: Kohn
mesh_terms: D000818:Animals; D008252:Macaca fascicularis; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D010775:Photic Stimulation; D015348:Vision, Binocular / Q000502:physiology; D015349:Vision, Monocular / Q000502:physiology; D014793:Visual Cortex / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*
keywords: 3D motion; IOVD; area MT; binocular vision; motion-in-depth; stereomotion