Inhibitory control is relevant to many clinical disorders, including substance abuse/dependence, obsessive-compulsive disorder, and attention-deficit hyperactivity disorder. This proposal is designed to assess brain networks related to response inhibition in healthy young adults, and use neuromodulation to change these networks and behavioral performance on a response inhibition task. Having an understanding of the brain mechanisms involved in response inhibition may enable us to improve pre-existing treatments for disorders with inhibitory control difficulties.