This project will investigate the basal ganglia in autism, specifically reward and implicit learning systems, using functional and structural magnetic resonance imaging (MRI). Brain regions within the basal ganglia in the brain, including the ventral striatum and nucleus accumbens, are involved in motor learning and the processing of rewards. Therefore, disruption of this system could account for several core features of autism such as motor stereotypies, rigidity in learning and poor response to normally rewarding stimuli such as facial affect. Using established tasks which test reward learning, Dr. Bookheimer and Ms. Scott will determine if children with autism have a deficit in basal ganglia function in response to rewards. In addition, the size of subregions within the basal ganglia, including the nucleus accumbens, caudate and putamen will also be measured. Finally, the correlation between the activity and size of these regions and degree of functional impairment will be calculated. This project will relate the structural and functional findings to autism symptomatology, specifically measures of repetitive behaviors, restricted interest, language, and overall severity of autistic symptoms. This project will expose the trainee to multiple research methods and provide a comprehensive introduction into responsible conduct of autism research. What this means for people with autism: This proposal will address key questions in the investigation of the underlying neurobiology of autism by examining a system implicated motor behavior, learning and reward processing, as well as provide training in the skills necessary to pursue an academic career in neuroimaging and autism research for the trainee.