His research focuses onhuman sleep and circadian neurobiology. Address: 3801 Miranda Avenue (151Y), Palo AltoCA 94304, USA. [email: jzeitzer@stanford.edu] Jerome Yesavage, MD, is Professor of Psychiatry and Behavioral Sciences at StanfordUniversity School of Medicine. Address: Stanford, CA 94305-5550, USA. [email:yesavage@stanford.edu]