Imposing demands on precision influences the hands differently during alternated discrete touching

Purpose. How demands of precision influence the performance during alternated discrete touching is not well established in the literature. Hence, we compared both hands performance during alternated touching, manipulating the precision demand. Methods. Overall, 23 right-handed adults participated in this study. the first task consisted of alternated touching with a pencil on both sides of a blank paper, performing as fast as possible, considering the first touch as reference for the next ones. Subsequently, touch dispersion and width were measured, and circular targets were drawn with those proportions. the second task consisted of performing as many hits as possible inside those targets. Apart from the delimitated target, increasing precision demand, the task parameters were equal. Results. Movement time increased and the number of touches decreased from the first to the second task. However, the preferred hand displayed greater reductions in performance. Conclusions. the perceptual constraint of adding a visual target affects motor control parameters in alternated touching, causing decrements in performance in both hands, but more evidently in the preferred right hand.