Latest research shows that yawning helps in keeping the brain cool, contradicting the popular belief that yawning promotes sleep and is a sign of tiredness.
Yawning involves opening the mouth involuntarily while taking a long, deep breath of air. It is commonly believed that people yawn as a result of drowsiness or weariness because they need oxygen.
However, researchers at the University of Albany in New York said their experiments on 44 students showed that drawing in air helps cool the brain and helps it work more effectively.作者: hsl780404 时间: 2008-4-4 03:47
研究人员称，实验表明，提高或降低血液中氧气和二氧化碳的含量不会导致那种反应。
They said that their experiments showed that raising or lowering oxygen and carbon dioxide levels in the blood did not produce that reaction.
Study participants were shown videos of people laughing, being neutral and yawning, and researchers counted how many times the volunteers responded to their own 'contagious yawns,' reported the online edition of BBC News.作者: hsl780404 时间: 2008-4-4 03:47
研究人员发现，在看别人打呵欠的视频时，用鼻子呼吸的人比用口腔呼吸的人打呵欠的几率要小。这是因为鼻腔里的血管将温度较低的血液送到了脑部。
The researchers found that those who breathed through the nose rather than the mouth were less likely to yawn when watching a video of other people yawning. This was because vessels in the nasal cavity sent cool blood to the brain.作者: hsl780404 时间: 2008-4-4 03:48
将冰袋敷在前额上也能起到类似的效果，而在观看视频时用暖水袋或室温水袋敷在额头上的人却无法避免打呵欠。
The same effect was found among those who held a cool pack to their forehead, whereas those who held a warm or room-temperature pack yawned while watching the video.作者: hsl780404 时间: 2008-4-4 03:48
这份在《进化生理学》上发表的研究报告提到，“由于脑部温度上升时就会打呵欠，所以将低温血液送至大脑能够保持脑部效率的最佳水平。”
'Since yawning occurs when brain temperature rises, sending cool blood to the brain serves to maintain optimal levels of mental efficiency,' the authors wrote in the journal Evolutionary Psycology.作者: wwnw_007 时间: 2008-4-4 08:58 [s:83] [s:83] 得益了作者: frankpeng 时间: 2008-4-25 09:08
为何我好少哈欠．^_^ [s:3]作者: Jim-Guo 时间: 2008-5-17 17:21
那我以后天天炒辣椒,还加点胡椒粉,保证有哈欠打...
[s:83] [s:83] 得益了
[s:3]