40 right-handed adults with schizophrenia and no significant medical or neurological illness (18-30 years old) will 1) undergo fMRI during performance of a cognitive control task, then 2) randomize to an 8-week, double-blind antipsychotic treatment trial, followed by 3) repeat fMRI in a single-dose, counterbalanced study of Modafinil (one 200 milligram oral add-on dose) vs. Placebo (Placebo). Neuroimaging measures will be the primary endpoint, cognition secondary, and symptoms an exploratory endpoint.