1. Center for Sleep Medicine, Saiseikai Nagasaki Hospital, Nagasaki, Japan
2. Department of Psychiatry, Jikei University School of Medicine, Tokyo, Japan
3. Sleep & Circadian Neurobiology Laboratory, Stanford Sleep Research Center, Stanford University School of Medicine, Palo Alto, CA
4. NoruPro Light Systems, Tokyo, Japan
5. Department of Neuropsychiatry, Akita University School of Medicine, Akita, Japan