This thesis attempts to investigate issues relating to the programming of movements and the use of visual feedback in two series of experiments. The first series of experiments focus on movement planning and examine the influence of response complexity on both s imple and choice reaction time (RT). The aim here was to test whether differences in the response complexity effect between simple and choice RT tasks depend on the extent to which movements are programmed during RT versus during execution. The second series of experiments were designed to investigate the use of visual feedback in both the planning and execution of movements. The control of direction and amplitude components of aiming movement tasks were investigated at different movement times. Also of interest was the extent to which the utilisation of central a nd peripheral vision depended on where in the visual field information was presented or the time available to use this information. Theories developed from past research in this area are both expanded and re-examined using a new methodology whereby the variability in limb trajectories are analysed at various points during the movement in order to assess the relative contributions of on line and offline visual feedback in movement control.