Age differences in the expression of manual asymmetry.

Manual dexterity declines in older adults; however, the degree to which the decline is symmetrical in the two hands is less clear. In this investigation the differences between young (aged 18 to 24) and old (aged 62 to 72) men and women in the expression of manual asymmetry across several motor tasks were examined. Five motor tasks provided a broad measurement of several motor characteristics necessary for instrumental activities of daily living. The main effect of sex was not significant; therefore data from men and women were pooled. Little support was found for generalized asymmetrical performance in old adults compared to young adults across motor tasks. An age-by-hand group analysis indicated that age was related to preferred hand performance on two tasks, but when a within-subject analysis of hand differences was performed, and the speed accuracy trade-off considered, differential asymmetry was seen only in the most complex, speeded task.