Effects of age and gender on discrete and reciprocal aiming movements.

Using a cross-sectional design, this study determined the time course of aging effects on rapid discrete and reciprocal aiming movements in men and women. A total of 80 men and 61 women in good health were classified into six age groups (25, 35, 45, 55, 65, and 75 years). The discrete task required participants to make one discrete aiming movement, whereas the reciprocal task required a series of back-and-forth movements. Results indicated for both aiming tasks that greater age was strongly associated with slower movement times. The significant interaction between age and task indicated that the discrete task showed much larger aging effects (54%) than the reciprocal task (25%). This finding is tentatively interpreted in terms of a reduced efficiency of "on-line" control processes.