Abigail Person's laboratory studies the contribution of the cerebellum to motor control, focusing on circuit mechanisms that support smooth, precise movement. A central idea in cerebellar physiology is that the position of the body is monitored via copies of motor commands conveyed by "corollary discharge pathways". By combining physiology, optogenetics, anatomical methods, and behavior we address how cerebellar circuitry makes movements precise. These topics are at the heart of the role of the cerebellum as a sensorimotor integrator. Disorders of this circuitry are hypothesized to contribute to some aspects of disorders such as autism and schizophrenia as well as broad motor disturbances seen in cerebellar ataxias.