One of the defining characteristics of the human species is our massive repertoire of skills, and our astoundingly flexible capacity to learn new ones throughout life. From masters (Serena Williams, Mozart) to amateurs (the rest of us), skilled behavior leverages a variety of different psychological processes, neural circuits, and learning algorithms. The Action, Computation, and Thinking (ACT) Lab investigates the psychological and neural foundations of human skill learning. We use multiple methodological approaches, including behavioral experiments, computational modeling, neuroimaging, and neuropsychology.