1 Unit for Experimental Psychiatry, Division of Sleep and Chronobiology, Department of Psychiatry, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, USA. Electronic address: basner@pennmedicine.upenn.edu.
2 Unit for Experimental Psychiatry, Division of Sleep and Chronobiology, Department of Psychiatry, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, USA.
3 Sleep and Performance Research Center, Washington State University, Spokane, Washington, USA.
4 Sleep and Performance Research Center, Washington State University, Spokane, Washington, USA; Elson S. Floyd College of Medicine, Washington State University, Spokane, Washington, USA.