No Evidence that Binocular Vision Enhances Online Corrections for Reaches in the Lower-Visual Field

Some work has proposed that an increased density of retinal ganglion cells in the superior hemiretina elicits a functional advantage for goal-directed reaches in the lower visual field (i.e., loVF). Furthermore, reaches performed with binocular stereo-cues exhibit optimized feedback-based trajectory corrections (i.e., online control). The present study examined whether the purported loVF advantage is restricted to binocular reaches implemented via a primarily online mode of control. Participants completed binocular and monocular reaches to loVF and upper-visual field (i.e., upVF) targets. Separate groups were provided vision during response planning and control (i.e., closed-loop group: CL), or during response planning only (i.e., open-loop group: OL). The binocular condition and the CL group exhibited more online corrections than reaches in the monocular condition or OL group. Notably, however, for all experimental conditions loVF and upVF reaches did not reliably differ – a result demonstrating no systemic loVF advantage for online control