據(jù)4月24日的《科學(xué)》雜志報(bào)道說,，一項(xiàng)新型的腦成像研究可能幫助人們解釋為什么有些人在清晨思維最為敏捷,，而另外一些人則在傍晚的時(shí)候變得最有效率,。 Christina Schmidt及其在比利時(shí)和瑞士的同僚現(xiàn)在報(bào)告說,，我們的思維敏捷程度及思想集中的能力受到了我們已經(jīng)醒了多久以及當(dāng)時(shí)在一天中所處的時(shí)間的雙重影響,，因?yàn)槲覀兊纳镧姽?jié)奏是根據(jù)日-夜周期運(yùn)作的,。
研究人員應(yīng)用功能性核磁共振成像來對早起者和夜貓子的腦部活動(dòng)進(jìn)行監(jiān)控,。這些人在連續(xù)兩個(gè)夜晚呆在一個(gè)睡眠實(shí)驗(yàn)室中,，并周期性地從事一項(xiàng)需要保持持續(xù)注意力的作業(yè)。 研究的結(jié)果提示,，一般來說,，夜貓子在他們發(fā)生腦疲勞之前，其清醒的時(shí)間會比早起者長,。 在清醒10個(gè)小時(shí)之后,，與夜貓子相比，早起者的與注意力有關(guān)系的腦部區(qū)域的活動(dòng)性會有所下降,。 早起者還更容易感到困乏,，并容易使作業(yè)操作變得更慢。 這些腦區(qū)域包括生物主時(shí)鐘的所在地,。 該區(qū)域的活動(dòng)會降低實(shí)驗(yàn)自愿者清醒的時(shí)間（即“睡眠壓力”增加了）,，提示早起者和夜貓子之間的行為差異至少有一部份與控制睡眠壓力和生理節(jié)奏有關(guān)的腦區(qū)域間的相互作用的結(jié)果有關(guān)。（生物谷Bioon.com）
生物谷推薦原始出處：
Science 24 April 2009:DOI: 10.1126/science.1167337
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.
1 Cyclotron Research Centre, University of Liège, 4000 Liège, Belgium.
2 Cognitive and Behavioral Neuroscience Centre, University of Liège, 4000 Liège, Belgium.
3 PHYSIP S.A., 75011 Paris, France.
4 Centre for Chronobiology, Psychiatric Hospital of the University of Basel, CH-4025 Basel, Switzerland.
5 Neuropsychology and Functional Neuroimaging Research Unit (UR2NF), Université Libre de Bruxelles, B-1050 Brussels, Belgium.
