Circadian Rhythm and Sleep During Prolonged Antarctic Residence at Chinese Zhongshan Station

摘要

Objective.-Residence at Zhongshan Station (69 degrees 22'24 '' S, 76 degrees 22'40 '' E) for over 1 year exposes winter-over members to marked changes of light dark cycle, ranging from the constant daylight of polar days to the constant darkness of polar nights, in addition to geographic and social isolation. This extreme photoperiodic environment may increase the risk of sleep disturbances and circadian desynchrony. The aim of this study was to investigate the circadian rhythm and sleep phase of Chinese winter-over expeditioners at Zhongshan Station.