This is an individual National Research Service Award for pre-doctoral research training, which provides support for promising doctoral candidates who will be performing dissertation research and training in a scientific health-related field. The basal ganglia (BG) system has been implicated in learning and memory, language, motor behaviors, and social communication, all of which are disrupted in autism spectrum disorders (ASD). This study will investigate the BG in autism as a possible core neurobiological component of the disorder using both structural and functional magnetic resonance imaging (fMRI). The study will use an established implicit learning task, which has been shown to rely on the BG, and add a reward component to test the hypothesis that ASD children will show less activity in this area compared to typically developing children. Beyond investigating functional deficits in the basal ganglia, this research will also explore the underlying link between neural structure to behavior by relating the functional and structural measures to measures of repetitive behaviors, restricted interests, and overall severity of autistic symptoms. By addressing relationships between behavior, structure, and function of one system in both children with and without autism, a clearer picture of how implicit learning and reward system dysfunction may contribute to some of the core deficits in autism will emerge.