Motor stability in visuomotor control of repetitive hand movements and its differential cerebral control in right-handed subjects.

The stability of asymmetric motor control was studied in right-handed subjects. Hand skill was assessed by a peg moving task in ten trials. The mean peg moving time (PMT) and its standard deviation (SD) were calculated for each hand. Standard deviation was taken as an index of the stability of visuomotor control. The mean rate of a repetitive movement (mean PMT) did not always show an association with its stability (SDs). This depended upon familial sinistrality, sex, and cerebral lateralization such as eye and foot preferences of the subjects. The left-right differences in movement stabilities also showed different contributions of the right and left brains of the subjects depending upon these factors. It was suggested that these factors should be taken into consideration in studies concerning the hemispheric control of especially corrective components of skilled movements of hands.