7 tesla FMRI reveals systematic functional organization for binocular disparity in dorsal visual cortex.


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Authors
Goncalves, Nuno R 
Ban, Hiroshi 
Sánchez-Panchuelo, Rosa M 
Francis, Susan T 
Schluppeck, Denis 
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.

Description
Keywords
V3A, binocular disparity, fMRI, psychophysics, ultra-high-field imaging, visual cortex, Adult, Brain Mapping, Female, Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Male, Oxygen, Photic Stimulation, Probability, Vision Disparity, Visual Cortex
Journal Title
J Neurosci
Conference Name
Journal ISSN
0270-6474
1529-2401
Volume Title
7
Publisher
Society for Neuroscience
Sponsorship
Wellcome Trust (095183/Z/10/Z)
European Commission (290011)
This work wassupported by the European Community’s Seventh Framework Programme FP7/2007-2013 (Grant PITN-GA- 2011-290011), the Japan Society for the Promotion of Science (JSPS KAKENHI Grant 26870911), and the Wellcome Trust (Grant 095183/Z/10/Z).