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. Author manuscript; available in PMC: 2011 Jul 5.
Published in final edited form as: J Biol Rhythms. 2008 Aug;23(4):353–361. doi: 10.1177/0748730408318081

Figure 3.

Figure 3

Circadian rhythm in sleep inertia and sleep efficiency according to time into sleep episode. Sleep inertia after awakening from combined sleep stages exhibits a similar circadian rhythm amplitude and phase for each of the 3 tertiaries, with a peak at 300°. In contrast, sleep efficiency shows no circadian rhythm during the first tertiary and a very large rhythm during the last tertiary. Filled symbols indicate the increase in number of correct additions across the first 20 min following awakening as a measure of dissipation of sleep inertia. Open symbols indicate sleep efficiency (total sleep time as a percentage of scheduled sleep episode). Error bars indicate SEM; n = 9 subjects (3 subjects were excluded due to incomplete data, e.g., due to inhaler use).