Practice and Component Submovements: The Roles of Programming and Feedback in Rapid Aimed Limb Movements.

An experiment is reported in which subjects (N = 30) practiced rapid aimed limb movements (wrist rotations), with either full visual feedback, no visual feedback, or delayed visual feedback. Previous research has indicated that, with practice, subjects increase the distance and duration of ballistic primary submovements and decrease the distance and duration of corrective secondary submovements. The design of the present experiment permitted the determination of whether these practice-related changes are results of improved programming of the primary submovement or of more efficient processing involved in the production of secondary submovements. The results suggest that improved programming occurs with practice. Furthermore, it appears that visual feedback is not solely responsible for the production of secondary submovements.