Fig. 8.

Regression of personal grip force variation against slacking rate. Participants with greater average slacking rates (measured during error-clamp trials) exhibited significantly greater force variation during control trials (both measures were averaged over the 4 highest force levels with both hands included). Between-participant variability in slacking rate explained 29% of the variability in the magnitude of their force variation. This correlation may describe the need for more frequent and dramatic corrections by the participants whose faster slacking rates led to more frequent and dramatic tracking errors. CV, coefficient of variation; MVC, maximum voluntary contraction.