Is it the dominant or ipsilateral eye that contributes to online visuomotor control the most?


Using the dominant limb (Apker et al., 2015) or gathering visual information from the dominant eye (Manzone et al., 2018) is advantageous for the control of goal-directed action. Further, participants were better able to correct for an imperceptible target jump during right limb trajectories when brief visual samples were provided to the ipsilateral (i.e., right) eye relative to their initial hand position (i.e., rightward home position) compared to contralateral combinations (e.g., left eye, rightward home position; Loria et al., 2019). But, movements were only performed with the dominant right hand and all participants were right eye dominant. Therefore, it is unclear whether the ipsilateral combination of eye, home position and hand or the coupling of the dominant eye and hand contributes to the corrections. In the current study, participants performed left-handed and right-handed reaches toward an imperceptibly jumped target from home positions located to the left and right of the midline. All participants were right hand and eye dominant. After movement onset, only a brief visual sample was provided to the left and/or right eye. This created two ipsilateral conditions: one with the dominant eye and hand (i.e., ipsilateral dominant) and one without (i.e., ipsilateral non-dominant). Significant corrections toward the jumped target position were found in the ipsilateral dominant condition (i.e., right hand, eye, home) but not the ipsilateral non-dominant condition (i.e., left hand, eye, home). This suggests that it is indeed the coupling of only the dominant eye and hand in ipsilateral space that contributes to online visuomotor control.

Acknowledgments: University of Toronto, Ontario Research Fund, Canadian Foundation for Innovation, National Sciences and Engineering Research Council