title: Dynamics and cortical distribution of neural responses to 2D and 3D motion in human.
abstract: The perception of motion-in-depth is important for avoiding collisions and for the control of vergence eye-movements and other motor actions. Previous psychophysical studies have suggested that sensitivity to motion-in-depth has a lower temporal processing limit than the perception of lateral motion. The present study used functional MRI-informed EEG source-imaging to study the spatiotemporal properties of the responses to lateral motion and motion-in-depth in human visual cortex. Lateral motion and motion-in-depth displays comprised stimuli whose only difference was interocular phase: monocular oscillatory motion was either in-phase in the two eyes (lateral motion) or in antiphase (motion-in-depth). Spectral analysis was used to break the steady-state visually evoked potentials responses down into even and odd harmonic components within five functionally defined regions of interest: V1, V4, lateral occipital complex, V3A, and hMT+. We also characterized the responses within two anatomically defined regions: the inferior and superior parietal cortex. Even harmonic components dominated the evoked responses and were a factor of approximately two larger for lateral motion than motion-in-depth. These responses were slower for motion-in-depth and were largely independent of absolute disparity. In each of our regions of interest, responses at odd-harmonics were relatively small, but were larger for motion-in-depth than lateral motion, especially in parietal cortex, and depended on absolute disparity. Taken together, our results suggest a plausible neural basis for reduced psychophysical sensitivity to rapid motion-in-depth.
authors.affiliation: Centre de Recherche Cerveau et Cognition, Centre National de la Recherche Scientifique CERCO UMR 5549, Toulouse, France;
authors.forename: Benoit R
authors.initials: BR
authors.lastname: Cottereau
authors.forename: Suzanne P
authors.initials: SP
authors.lastname: McKee
authors.forename: Anthony M
authors.initials: AM
authors.lastname: Norcia
mesh_terms: D000328:Adult; D000368:Aged; D001931:Brain Mapping; D003867:Depth Perception; D005074:Evoked Potentials, Visual; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009039:Motion Perception; D009474:Neurons / Q000502:physiology*; D014793:Visual Cortex / Q000166:cytology / Q000502:physiology*
keywords: 3D; high-density EEG; stereomotion; vision