Abstract
Ample research has investigated the advantage of binocular over monocular vision. In this study, we aimed to better understand the use of monocular vs. binocular visual feedback for the control of on-going upper-limb reaching movements. If binocular cues (e.g., binocular disparity) contribute to such online control processes, then participants should exhibit wider endpoint distributions when performing with one vs. two eyes. Twelve right-eye and right-hand dominant individuals performed reaching movements (30 cm) with counterbalanced presentation of monocular dominant, monocular non-dominant and binocular vision conditions. We analysed movement endpoint accuracy and precision. As anticipated, participants exhibited wider endpoint distributions in the primary movement axis, with both monocular conditions compared to the binocular condition. In addition, we performed contrasts between limb position at 25%, 50% and 75% of movement time and limb position at movement end. Such correlational analyses presumably reflect the extent to which movements are corrected between movement onset and offset (e.g., Heath, 2005). Further, analysis of the Fisher-z transformed R values showed that participants exhibited more stereotyped (i.e., less controlled) trajectories in the monocular dominant condition compared to the binocular vision condition. The contrast between monocular non-dominant and binocular vision failed to reach significance. These results provide evidence that individuals employ binocular cues (e.g., binocular disparity) to implement online trajectory amendments while vision with the dominant eye vs. the non-dominant eye contribute differently to the control of on-going movements.
Meeting abstract presented at VSS 2014