New research led by a team of researchers from Binghamton University, USA concludes that yawning may be linked to brain temperature and is a way to cool the brain. One often notices that people who are tired yawn often. Fatigue and sleep deprivation causes an increase in deep brain temperature and yawning helps cool the brain down. Researchers have compared the brain to a computer and point out that complex machines like the computer operate most efficiently when they are kept cool. Without a fan, a computer would soon overheat and grind to a halt. Similarly, the yawn keeps the brain from overheating. Yawning also seems to be part of a transitional state for the brain, as in the periods just before sleep and just after waking. Certain researchers
also say that the brain signals for a yawn when it needs more oxygen.