From the Carolina Institute for Developmental Disabilities and the Department of Psychiatry, University of North Carolina, Chapel Hill; the Department of Psychiatry and the Department of Radiology, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis; the Department of Radiology and the Department of Speech and Hearing Sciences, University of Washington, Seattle; the Scientific Computing and Imaging Institute, University of Utah, Salt Lake City; the Center for Autism Research, Children's Hospital of Philadelphia, University of Pennsylvania; and the Montreal Neurological Institute, McGill University, Montreal.