Many believe that yawning serves to increase the oxygen supply to the brain, but a new study has shown that the purpose of yawning is actually cooling the brain.
A team of scientists from SUNY College at Oneonta believes that previous studies failed to find a link between yawning and blood oxygen levels. They say that changes in the temperature of the brain associated with sleep cycles, the degree of alertness of the cerebral cortex and the level of stress. Therefore, assuming that the yawning may affect temperature variations in the environment and changes of cold air through the yawning can lower the temperature of the brain and lead to optimal homeostasis. Also, consider that the yawning occur only within a certain ‘thermal window’ or within the optimal temperature range.
Scientists from the University of Vienna, went a step further in exploring yawning and measured the frequency of infectious yawning with walkers near Vienna during the winter and summer months, and then the results were compared with similar studies conducted in the dry climate of Arizona.
Contagious yawning cools the brain, thereby improving mental effectiveness, say Austrian scientists. The results showed that the respondents in Vienna yawning more in winter than in summer.
The authors of the study believe that yawning is useless when the outdoor temperature is the same as body temperature, and harmful when they are out extremely low temperatures and therefore in such circumstances rarely full of yawning.
“When someone in your company yawned (and thus provide cooling your brain to be able to be alert and awake), it is possible that this person noticed something threatening and therefore wants to cool the brain to be the more awake, and then automatically you yourself want to cool your brain to achieve alertness and so you start to yawn. But all this is completely unaware of the mechanism, “explained study author Dr. Massen.