The purpose of this study is to explore the effects of genes and genetic variation on brain structure and function. Investigators at Harvard plan to explore the relationship between candidate genes that affect cognitive performance and brain structure/function. Since brain phenotypes reflect more proximal sequelae of gene activity, neuroimaging measures may show greater sensitivity than cognitive performance to measure gene effects.

Inclusion Criteria:

1. 13 years or older
2. Subject must have a current DSM-IV diagnosis of high functioning ASD, based on past evaluations at the Bressler Clinic.
3. Subjects must have a level of understanding sufficient to communicate intelligently with the investigator and study coordinator, and to cooperate with all tests and examinations required by the protocol.
4. Each subject must understand the nature of the study. The subject must sign an IRB approved informed consent.

Exclusion Criteria:

1. IQ < 70 bassed on evaluation in the Bressler Clinic.
2. Contraindication to MRI including presence of metal or surgical devices (plates, implants, braces or other items).
3. Neuropsychiatric conditions (such as dementia) which sufficiently impair cognition such that a surrogate consent would be required.
4. Neurological disorders associated with gross brain pathology (other than atrophy), e.g., stroke, tumors, or demyelinating diseases.
5. Pregnancy.

Adults with Autism Spectrum Disorders ages 13 and older.