Citation

Cottereau BR, McKee SP, Norcia AM. J. Neurophysiol. 2014; 111(3): 533-543.

Affiliation

CerCo, CNRS UMR5549.

Copyright

(Copyright © 2014, American Physiological Society)

DOI

10.1152/jn.00549.2013

PMID

24198326

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 fMRI-informed EEG source-imaging to study the spatio-temporal 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 inter-ocular phase - monocular oscillatory motion was either in-phase in the two eyes (lateral motion) or in anti-phase (motion-in-depth). Spectral analysis was used to break the steady-state visually evoked potentials (SSVEP) responses down into even and odd harmonic components within five functionally defined regions of interest (ROIs): V1, V4, lateral occipital complex (LOC), 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 ROIs, 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.

Language: en