Can Human Isochrony be Explained by a Computational Theory?

Previous studies on human motor control reported a phenomenon called isochrony, which is the compensatory increase of movement speed with increasing movement distance. On the other hand, in complex via-points trajectory formation, a possible computational model that can estimate via-point time has been proposed. This model is optimized on the condition that the Duration average of the Commanded Torque Change (DCTC) between each via-point is equal. In this paper, we consider the possibility that human isochrony can be explained by the computational theory and investigate the human drawing movement of a set of figure eight and double elliptical patterns. Results show that isochrony was observed in both duration and DCTC and that relative variance with an increasing movement perimeter ratio of DCTC was significantly less than duration. The possibility is suggested that human isochrony is a phenomenon observed as a result of movement time planning to equalize DCTC