One foundation of learned behavior is the ability to associate arbitrary combinations of stimuli and actions. After learning a sensorimotor association, the brain transforms previously meaningless stimulus information into a specific motor command, but it is unclear where this transformation occurs and how it develops across learning. We are investigating how the cortex-basal ganglia circuit is involved in this type of learning by recording widespread activity while mice perform simple sensorimotor tasks. Our findings are building towards a cascade of events during learning, where sensory responses are increased in the basal ganglia, funneled into behavioral relevance, and routed to motor regions of the cortex. Surprisingly, this cascade appears to be different for visual and auditory stimuli, suggesting possible specialized circuits depending on the modality.