Inclusion Criteria:  Men and women aged 18- 55 years that are physically and mentally healthy with the exception of DSM-5 schizophrenia or schizoaffective disorder diagnosis Subjects with no metal in the body that may pose a risk during MRI scanning No significant medical history, including head trauma and bleeding disorders  Exclusion Criteria:  Men and women with a history or presence of clinically significant medical conditions Smokers who are unable to abstain from cigarette use for 5 days People who suffer from claustrophobia, have MRI incompatible implants, or other contraindications for MRI and PET scans