[1] Kennedy Krieger Inst, Ctr Autism & Related Disorder, Baltimore, MD 21286 USA
[2] Johns Hopkins Univ, Sch Med, Dept Psychiat & Behav Sci, Baltimore, MD 21205 USA
[3] Univ Colorado, Sch Med, Anschutz Med Campus, Aurora, CO USA
[4] Cincinnati Childrens Hosp Med Ctr, Cincinnati, OH 45229 USA
[5] Univ N Carolina, Dept Psychiat, TEACCH Autism Program, Chapel Hill, NC USA
[6] Univ N Carolina, Dept Psychol, TEACCH Autism Program, Chapel Hill, NC USA