Effect of Visual Information on Dominant and Non-dominant Hands During Bimanual Drawing with a Robotic Platform

In a stable bimanual trajectory tracing task with interlimb spatial and temporal synchrony, blocking the visual information from one hand may alter the performance of either hand. In this paper, we investigate the effect of visual information on motor behaviour of dominant and non-dominant hands during a bimanual task, with a focus on motor lateralization theory's anticipation for a more pronounced distortion on one hand due to visual information withdrawal. To address this question, four bimanual circle tracing experiments were designed with two rehabilitation robotic arms with real time visual feedback. Two experiments were conducted under the free-visual condition whereas the visual feedback from one hand was blocked for the other two. The in-depth analysis of the metrics extracted from 685 circles, drawn by 6 participants, revealed that non-dominant hand, when visible, generally performs worse than the dominant hand, for instance it exhibits less circularity. In their invisible modes, the performance of the dominant and non-dominant hands displayed inconsistent difference across the participants. Moreover, both hands showed a higher pace when partial visual information was available. Our findings using this robotic framework as a systematic tool on developing new paradigms are discussed.