Homeostatic Sleep Pressure and Responses to Sustained Attention in the Suprachiasmatic Area

Science 24 April 2009:
Vol. 324. no. 5926, pp. 516 - 519
DOI: 10.1126/science.1167337
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Homeostatic Sleep Pressure and Responses to Sustained Attention in the Suprachiasmatic Area
Christina Schmidt,1,2,* Fabienne Collette,1,2 Yves Leclercq,1 Virginie Sterpenich,1 Gilles Vandewalle,1 Pierre Berthomier,3 Christian Berthomier,3 Christophe Phillips,1 Gilberte Tinguely,1 Annabelle Darsaud,1 Steffen Gais,1 Manuel Schabus,1 Martin Desseilles,1 Thien Thanh Dang-Vu,1 Eric Salmon,1 Evelyne Balteau,1 Christian Degueldre,1 André Luxen,1 Pierre Maquet,1 Christian Cajochen,4 Philippe Peigneux1,5,*

Throughout the day, cognitive performance is under the combined influence of circadian processes and homeostatic sleep pressure. Some people perform best in the morning, whereas others are more alert in the evening. These chronotypes provide a unique way to study the effects of sleep-wake regulation on the cerebral mechanisms supporting cognition. Using functional magnetic resonance imaging in extreme chronotypes, we found that maintaining attention in the evening was associated with higher activity in evening than morning chronotypes in a region of the locus coeruleus and in a suprachiasmatic area (SCA) including the circadian master clock. Activity in the SCA decreased with increasing homeostatic sleep pressure. This result shows the direct influence of the homeostatic and circadian interaction on the neural activity underpinning human behavior.