Seasonal changes in human sleep–wake rhythm in Antarctica and Japan

• Published in: Psychiatry and Clinical Neurosciences
• Main Authors: Usui, Akira, Obinata, Ichio, Ishizuka, Yoshikazu, Okado, Tamio, Fukuzawa, Hitoshi, Kanba, Shigenobu
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2000
• Subjects: Antarctic; Midwinter; The Antarctic; Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1046/j.1440-1819.2000.00715.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1440-1819.2000.00715.x; https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1440-1819.2000.00715.x; https://onlinelibrary.wiley.com/doi/full-xml/10.1046/j.1440-1819.2000.00715.x

Abstract The subjects were eight men of the Japanese Antarctic Research Expedition (average age 35.8 years), and 10 healthy people living around Kofu, Japan (28.9 years). They completed a sleep log for 12 to 18 months, and the sleep–wake state was scored in 10‐min epochs. Q 24 values calculated by χ 2 periodgram were low in the Antarctic midwinter. This means that there was difficulty in synchronizing to a 24‐h period in the Antarctic midwinter. In Antarctica, sleep onset and offset times were delayed mostly in the midwinter. In Japan, sleep offset time was delayed mostly around the winter solstice.