I study how people learn new movements. This involves identifying the objective that governs movement, the steps that the nervous system takes to discover these new movements, and the neural systems that implement these steps. My past work concerned the objective that governs everyday movements like walking. Now, my work uses simple movements like reaching to ask how people learn to select the best actions through the process of reinforcement learning. My approach is to combine computational methods with behavioural experiments that test my hypotheses. To identify the neural systems that underlie action selection, these behavioural experiments include both neurologically healthy and impaired individuals. While this work is mostly fundamental, it may prove useful in developing new ways of rehabilitating movement, or new ways of controlling robots.