Ipsilateral eye contributions to online visuomotor control of right upper-limb movements.

A limb's initial position is often biased to the right of the midline during activities of daily living. Given this specific initial limb position, visual cues of the limb become first available to the ipsilateral eye relative to the contralateral eye. The current study investigated online control of the dominant limb as a function of having visual cues available to the ipsilateral or contralateral eye, in relation to the initial start position of the limb. Participants began each trial with their right limb on a home position to the left or right of the midline. After movement onset, a brief visual sample was provided to the ipsilateral or contralateral eye. On one third of the trials, an imperceptible 3 cm target jump was introduced. If visual information from the eye ipsilateral to the limb is preferentially used to control ongoing movements of the dominant limb, corrections for the target jump should be observed when movements began from the right of the body's midline and vision was available to the ipsilateral eye. As expected, limb trajectory corrections for the target jump were only observed when participants started from the right home position and visual information was provided to the ipsilateral eye. We purport that such visuomotor asymmetry specialization emerges via neurophysiological developments, which may arise from naturalistic and probabilistic limb trajectory asymmetries.