It’s no secret that yawning is contagious. But how to explain this phenomenon? This is the question posed by researchers at the University of Nottingham (United Kingdom). Their works, published in the journal Current Biology, reveal that contagious yawning is determined by the excitability of an area of the brain, the motor cortex, which is involved in the planning, control and execution of voluntary movements of the muscles of the body.
A discovery not so useless as that
To find out, the scientists used transcranial magnetic stimulation (TMS) on 36 volunteers, before asking them to watch videos showing other people yawning. The participants were separated into two groups: the first had to resist the urge to yawn, while the second had to let go. Their reactions were filmed and the researchers counted the number and type of yawns performed. They found that those who had to resist the urge to yawn had finally yawned more than the others. But that’s not all: they also observed that the urge to yawn was linked to the excitability of one’s motor cortex. “Some people have very excitable motor cortices and are very sensitive to contagious yawns, while others are much less,” says Stephen Jackson, lead author of the study, at Time.
A discovery that could be useful, especially in research on the disease of Gilles de la tourette : “If we could reduce excitability, we could reduce tics, and that’s what we’re working on,” concludes Georgina Jackson, co-author of this work.
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