A Single-Center, Double-Blind (DB) Study of MEM 3454 on P50 Sensory Gating and Mismatch Negativity in Schizophrenia Patients

Inclusion Criteria: * 1\. Male or female subjects between 18and 55 years of age. * 2\. Fluent in English, even if English is not the primary language. * 3\. Able to provide informed consent. * 4\. DSM IV-R primary diagnosis of schizophrenia (any subtype), assessed using a structured diagnostic interview (SCID CT). * 5\. Few or no extra-pyramidal symptoms(EPS)at screening,defined as SAS \< 6. * 6\. Negative urine drug screen (UDS). * 7\. Negative cotinine test. * 8\. Clinically stable, as judged by the investigator, and in a non-acute phase for at least 12 weeks. At least one month on the same dose of antipsychotic medication. Exclusion Criteria: * Current risk of suicide, or history of suicidal behavior within the last 6 months. * Hospitalized for psychiatric symptoms in the past 3 months. * Other psychiatric diagnoses. * Substance abuse/dependence (other than nicotine or caffeine) within the last 6 months according to the SCID-CT. * Currently smoking, nicotine replacement therapy, smoking cessation medications or remedies, including Varenicline (Chantix). * Any medical condition, as judged by the Investigator, which may interfere with the subjects' participation in this study.