DIFFERENTIAL ROLES WITH AGING OF VISUAL AND PROPRIOCEPTIVE AFFERENT INFORMATION FOR FINE MOTOR CONTROL

The goal of this study was to determine whether aging brings modificat ions to the role played by different sources of afferent information f or movement control. Older and younger subjects practiced an aiming ta sk for either 40 or 200 trials while different sources of afferent inf ormation were available. Following the practice phase, all subjects we re submitted to transfer tests in which the afferent information was e ither maintained or modified. Results indicate that modifying the sour ces of afferent information available for motor control from acquisiti on to transfer had minimal effects for the older subjects but caused l arge increase in error for the younger subjects. These results suggest that learning is specific to the sources of afferent information avai lable while practicing the task for the younger subjects, whereas olde r subjects skew more flexibility in their utilization of afferent info rmation for motor control.