Inclusion Criteria:

1. Male subjects between the ages of 8 - 10 years.
2. Not breast-fed during infancy
3. Right hand dominant
4. Attending school at appropriate grade level
5. Normal body-mass index (BMI)
6. Ability and willingness to provide assent and informed, written consent from at least one biological parent.
7. Present with biological parent
8. No current general medical or psychiatric illness.
9. Medication free.
10. Normal intelligence as assessed by the Kaufman Brief Intelligence Test.
11. Willingness to maintain current dietary habits.

Exclusion Criteria:

1. Inability or unwillingness to provide consent.
2. Antecedent or concurrent serious medical illness.
3. A lifetime history of any significant axis I psychiatric disorder ( i.e. bipolar disorder, schizophrenia)
4. Patients who have received any psychoactive medications, current and lifetime.
5. Clinically unstable medical disease, including cardiovascular, hepatic insufficiency, severe renal impairment, gastrointestinal, pulmonary, metabolic, endocrine, obesity or other systemic disease.
6. History of seizures, excluding febrile seizures in childhood.
7. Patients requiring treatment with any drug which might obscure the action of study the study treatment.
8. Less than normal intelligence.
9. Pacemaker
10. Cerebral aneurysm clip
11. Cochlear implant
12. Metal fragments lodged within the eye
13. Claustrophobia
14. Necessity of sedation (no sedation will be given).
15. History of loss of consciousness > 10 minutes in duration
16. Adopted