Training-induced dynamics of accuracy and precision in human motor control.

The study investigated the dynamic changes in accuracy and precision during a simple oral and digital motor task involving a controlled and a ballistic force. Eighteen healthy participants participated in four experimental sessions during which they performed one hundred trials of targeting a controlled (low/high hold force) and a ballistic force during an oral and a digital motor task (OMT and DMT). Accuracy and precision across one hundred trials were calculated and subjected to segmented linear regression analysis. Repeated performance of controlled forces show a significant dynamic change in accuracy during initial stage of targeting high hold forces during OMT and a significant dynamic change in both accuracy and precision during final stage of targeting high hold forces during DMT. Repeated performance of ballistic force showed a significant dynamic change in both accuracy and precision during final stage of targeting high hold force forces during OMT and a significant dynamic change in accuracy during the initial stages of targeting high hold force during the DMT. The findings indicate a subtle degree of dissociation between accuracy and precision in terms of dynamic modulation of forces due to repeated performance of both OMT and DMT.