Phase relationships between sleep-wake cycle and underlying circadian rhythms in Morningness-Eveningness.
Valérie Mongrain, Suzie Lavoie, Brahim Selmaoui, Jean Paquet, Marie Dumont
Journal of Biological Rhythms | Published : 2004
A shorter phase angle between habitual wake time and underlying circadian rhythms has been reported in evening types (E types) compared to morning-types (M types). In this study, phase angles were compared between 12 E types and 12 M types to verify if this difference was observed when the sleep schedule was relatively free from external social constraints. Subjects were selected according to their Morningness-Eveningness Questionnaire score (MEQ score). There were 6 men and 6 women in each group (ages 19-34 years), and all had a habitual sleep duration between 7 and 9 h. Sleep schedule was recorded by actigraphy and averaged over 7 days. Circadian phase was estimated by the hour of temperat..View full abstract