By yawning cool the brain

Yawning to thermoregulate the brain

07/05/2014

Yawning helps to regulate the temperature in the brain. This was the result of a study by scientists from the University of Vienna, Nova Southeastern University and SUNY College in Oneonta, USA. Accordingly, Viennese yawn more often in summer than in winter. A reverse Gähn behavior showed study participants from California. Accordingly, not the season but rather an optimal ambient temperature when yawning plays a role. The results of the study support the thesis currently being discussed in professional circles that yawning cools the brain. The current investigation was in the journal „Physiology and Behavior ".

Connection of temperature in the brain and yawning
To investigate the cause of yawning, the scientists led by Jorg Massen from the Department of Cognitive Biology at the University of Vienna conducted an experiment with 60 Viennese citizens in the winter of 2012/2013 and in the summer of 2013. The subjects looked at images of yawning people to yawn „infect“ allow. As it turned out, in the summer, 25 study participants (41.7 percent) actually yawned after looking at the pictures.„As expected, the percentage of yawning pedestrians was significantly lower in winter than in summer (18.3 percent versus 41.7 percent), with temperature being the only significant factor influencing these differences between seasons“, it says in the article. Although the scientists did not observe the subjects yawning, so that they do not feel observed and suppress the reflex, but they measured the current temperature. „We found that temperature is significantly associated with the frequency of yawning, with larger yawning numbers reported at higher temperatures, "the journal said.

In a previous study conducted in California, the scientists found that the subjects showed a contrary behavior when yawning. In the summer they were obviously too hot to yawn, so they did this more often in the winter. At this time of year, temperatures in California are around 20 degrees Celsius, similar to summer in summer. „Yawning as thermoregulation for the brain can not work if the ambient temperature and body temperature are the same. At ambient temperatures around freezing, this is also not necessary - or even dangerous, "Massen quoted in a statement from the university.

Yawning is not related to the oxygen content of the blood
The scientists also pointed out in their article that the often suspected connection between yawning and lack of oxygen is not proven. „While it is generally accepted that yawning fulfills a respiratory function, experimental procedures have shown that the yawn frequency is independent of the oxygen and carbon dioxide concentration in the brain / blood“, write the scientists. Experiments with rats and humans would have confirmed, however, that the temperature in the brain before yawning and a local heat accumulation arises. After yawning, the temperature drops again.

„In addition to improving the basic understanding of why we yawn, the improved therapy and diagnosis of patients with thermo-regulatory problems is one of the possible applications“ These results, the researchers report. (Ag)