The purpose of this study is to better understand brain function and psychiatric and neurological illness when taking Invega or Risperdal. The objective is to compare the brain effects of Invega to Risperdal in patients with Schizophrenia. This comparison will be evaluated with PET imaging, fMRI, and neurological ratings and assessments.

Inclusion Criteria:

• are currently taking Risperdal and have been on the medication for at least three weeks
• are diagnosed with schizophrenia
• are able to provide written informed consent
• can safely have an MRI

Exclusion Criteria:

• are treatment resistant or intolerant to Risperdal
• have participated in another drug study in the past 28 days
• are pregnant or trying to become pregnant or are breastfeeding
• are colorblind
• have a history of alcohol, cannabis, or cocaine abuse within two weeks prior to the study
• have a current or past history of a major medical illness or have abnormal lab values which the study doctor feels is significant
• certain medications are also exclusionary including aripiprazole.