2500-year-old scientific mystery of why we yawn Bashny.Net

There is a theory that can dot the i

During a long conversation there is an irresistible desire to yawn. The more you struggle with it, the more desirable. As a result, it is impossible to resist. Psychologist Robert Provine in his lectures often notes, but does not take offense: yawning, laughing and belching are natural.



Provine seek answers to the thousand-year mystery of why we yawn? It is clear that out of boredom or fatigue, but it gives the body?

Perhaps the first is interested in the ancient Greek physician Hippocrates 2,500 years ago. He believed that yawning helps get rid of harmful air, especially during fever. Until the 19th century, other scientists have put forward a myriad of assumptions. It was said that yawning helps breathing - increases the oxygen content in the blood and removes carbon dioxide, but if that were true, then the frequency of yawns would depend on the concentration of oxygen and carbon dioxide in the air. Provine this version tested - asked for volunteers to breathe mixtures of different gases, but nothing changed.

Yawning is contagious. If we see, hear or read about yawning, then there is a probability of 50% that we too zevnёm. So, yawning may be a primitive form of communication, but what information it carries? We often yawn when tired, so yawning may help synchronize biological clocks of different people. More we yawn during stress. Olympic athletes often yawn before a competition, and the musicians before the concert.



Provine and other researchers believe that yawning could "restart the brain" - a sleepy person makes more alert and distracted to concentrate forces. Contagious yawning can help everyone achieve the same level of attention. In general, the mechanism is not very clear, but the French scholar Olivier Valyusinski suggests that yawning increases the concentration of cerebrospinal fluid near the brain, which causes a shift in the neural activity.

Dispute much. But there is a theory that can dot the i. The idea came from Andrew Gallup of the State University of New York. When he was a bachelor, I realized that yawning may cool the brain and prevents it from overheating. Intense movement of the jaw starts the flow of blood in the skull and cools it, and delivers deep breath of cool air in the sinuses, carotid artery and eventually to the brain. Airflow and evaporates excess mucus in the mouth.



Gallup conducted a test. Under normal circumstances, 48% of the subjects to yawn, but when they put a cold compress to the forehead, the yawn was only 9%. Breathing through the nose, which also cools the brain worked more effectively completely suppress the urge to yawn. So if you do not want embarrassment during a serious conversation - breathe nose.

That sounds reasonable, especially if you know that the body temperature rises a little before and after sleep. A slight cooling of the brain makes us more vigilant when we are bored. Yawning is contagious because it can help to focus the whole group.

Some researchers do not agree with Gallup, because conclusive evidence he has not provided - in particular, had a direct measurement of the temperature of the human brain. But Gallup has experimented with rats and the results were positive.

But even if the hypothesis is true, the question remains much. For example, why the fetus yawning in the womb? Provine believes that this baby is ready for life, or yawning develops articulation of jaw compositions, or contributes to the lungs.

Sexual pleasure, sneezing and yawning, and gradually increase the culmination of a pleasant end. Therefore, Provine believes that the basis of these different senses is shared neural machinery.

Bet while reading you yawn several times. This is natural, so it enjoys one of the oldest mysteries of life.

via factroom.ru