Tuesday, September 20, 2011

Yawning is linked to regulation of brain temperature

Have you ever found yourself yawning in response to watching other people yawn? This is mostly regarded as a socially developed phenomenon, but new research shows that there might actually be a physiological mechanism driving this behavior. While most of us would think that yawning is a sign of sleepiness, Americans researchers have discovered that people tend to yawn less during the summer. This was tested in the desert climate of the American state of Arizona, which has a relatively large difference in average temperature between summer and winter. According to the scientists, the percentage of participants who yawned in response to seeing pictures of yawning people differed significantly between the two seasons:  in the winter, with lower ambient temperatures, the proportion of people who yawned was much greater, adding to the hypothesis that yawning is a so-called thermoregulator. Therefore, yawning could be a mechanism to cool off the brain, despite simply being regarded as an indication of sleepiness.

The scientists determined that 45 percent of the participants yawned in response to being shown pictures of people yawning, when the test was conducted in winter. In summer, only 22 percent was found to be yawning. Also, the tendency to yawn appears to be associated with time spent outside. During high temperatures in summer, a longer time spend outside is associated with decreased yawning, while in winter, the opposite was found.

According to the American researchers, their results show that yawning in response to observing other people yawning is not simply a social phenomenon. While they claim it might be a mechanism to cool off the brain, this hypothesis still remains largely untested. In order to prove that yawning is in fact a thermoregulator, brain temperature should be measured while yawning at different ambient temperatures. I reckon it will be a tad bit harder to find participants for such a study, as brain probes for temperature measurements are not likely to be popular.

Whatever the reason, the seasonal variance in the tendency to yawn is peculiar.

No comments:

Post a Comment