Study Evaluating Effects of SAM-531 on Sleep Electroencephalogram (EEG) and Quantitative Wake EEG in Healthy Subjects

Inclusion Criteria: * Men or women of non-childbearing potential aged 18 to 50 years inclusive on study day 1. * Body mass index in the range of 18 to 30 kg/m2 and body weight greater than or equal to 50 kg. * Healthy as determined by the investigator on the basis of medical history, physical examination, clinical laboratory test results, vital sign measurements, and 12-lead electrocardiogram. Exclusion Criteria: * Any significant cardiovascular, hepatic, renal, respiratory, gastrointestinal, endocrine, immunologic, dermatologic, neurologic, hematologic, neurologic, or psychiatric disease. * Clinically significant abnormal standard EEG at screening. * Consumption of any caffeine-containing products or alcoholic beverages within 48 hours before study day 1.