title: 7 tesla FMRI reveals systematic functional organization for binocular disparity in dorsal visual cortex.
abstract: The binocular disparity between the views of the world registered by the left and right eyes provides a powerful signal about the depth structure of the environment. Despite increasing knowledge of the cortical areas that process disparity from animal models, comparatively little is known about the local architecture of stereoscopic processing in the human brain. Here, we take advantage of the high spatial specificity and image contrast offered by 7 tesla fMRI to test for systematic organization of disparity representations in the human brain. Participants viewed random dot stereogram stimuli depicting different depth positions while we recorded fMRI responses from dorsomedial visual cortex. We repeated measurements across three separate imaging sessions. Using a series of computational modeling approaches, we report three main advances in understanding disparity organization in the human brain. First, we show that disparity preferences are clustered and that this organization persists across imaging sessions, particularly in area V3A. Second, we observe differences between the local distribution of voxel responses in early and dorsomedial visual areas, suggesting different cortical organization. Third, using modeling of voxel responses, we show that higher dorsal areas (V3A, V3B/KO) have properties that are characteristic of human depth judgments: a simple model that uses tuning parameters estimated from fMRI data captures known variations in human psychophysical performance. Together, these findings indicate that human dorsal visual cortex contains selective cortical structures for disparity that may support the neural computations that underlie depth perception.
authors.affiliation: Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, United Kingdom.
authors.forename: Nuno R
authors.initials: NR
authors.lastname: Goncalves
authors.affiliation: Center for Information and Neural Networks, National Institute of Information and Communications Technology, Suita City, Osaka, 565-0871, Japan, Graduate School of Frontier Biosciences, Osaka University, Suita City, Osaka 565-0871, Japan, and.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ban
authors.affiliation: Sir Peter Mansfield Magnetic Resonance Centre, School of Physics and Astronomy, and.
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Sánchez-Panchuelo
authors.affiliation: Sir Peter Mansfield Magnetic Resonance Centre, School of Physics and Astronomy, and.
authors.forename: Susan T
authors.initials: ST
authors.lastname: Francis
authors.affiliation: Visual Neuroscience Group, School of Psychology, University of Nottingham, Nottingham NG7 2RD, United Kingdom.
authors.forename: Denis
authors.initials: D
authors.lastname: Schluppeck
authors.affiliation: Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, United Kingdom, aew69@cam.ac.uk.
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Welchman
mesh_terms: D000328:Adult; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D011336:Probability; D015357:Vision Disparity / Q000502:physiology*; D014793:Visual Cortex / Q000098:blood supply* / Q000502:physiology*
chemical_list: D010100:Oxygen
keywords: V3A; binocular disparity; fMRI; psychophysics; ultra-high-field imaging; visual cortex