AUTHOR=Arnoldussen David M. , Goossens Jeroen , van Den Berg Albert V. 

TITLE=Dissociation of retinal and headcentric disparity signals in dorsal human cortex

JOURNAL=Frontiers in Systems Neuroscience

VOLUME=9

YEAR=2015

URL=https://www.frontiersin.org/journals/systems-neuroscience/articles/10.3389/fnsys.2015.00016

DOI=10.3389/fnsys.2015.00016

ISSN=1662-5137

ABSTRACT=<p>Recent fMRI studies have shown fusion of visual motion and disparity signals for shape perception (Ban et al., <xref ref-type="bibr" rid="B6">2012</xref>), and unmasking camouflaged surfaces (Rokers et al., <xref ref-type="bibr" rid="B54">2009</xref>), but no such interaction is known for typical dorsal motion pathway tasks, like grasping and navigation. Here, we investigate human speed perception of forward motion and its representation in the human motion network. We observe strong interaction in medial (V3ab, V6) and lateral motion areas (MT<sup>+</sup>), which differ significantly. Whereas the retinal disparity dominates the binocular contribution to the BOLD activity in the anterior part of area MT<sup>+</sup>, headcentric disparity modulation of the BOLD response dominates in area V3ab and V6. This suggests that medial motion areas not only represent rotational speed of the <italic>head</italic> (Arnoldussen et al., <xref ref-type="bibr" rid="B5">2011</xref>), but also translational speed of the <italic>head</italic> relative to the scene. Interestingly, a strong response to vergence eye movements was found in area V1, which showed a dependency on visual direction, just like vertical-size disparity. This is the first report of a vertical-size disparity correlate in human striate cortex.</p>