"Using electrical stimulation we were able to increase excitability and in doing so increase the propensity for contagious yawning", said Georgina Jackson, a Professor at the University of Nottingham.
Just thinking about yawning makes us yawn, and now scientists think they've figured out why yawning is so contagious. But their efforts to look less exhausted had clearly failed, because they yawned just as many times as under normal conditions. During the experiments, the participants were asked to estimate their urge to yawn on a sliding scale. Half of them were told to ignore the urge to yawn, while the other half were told to yawn when they felt like it. They recruited 36 adult participants and showed them video clips of other people yawning, instructing them to either try and stifle the yawn or let it rip. That in turn boosted people's propensity for contagious yawning.
What the researchers concluded is that instructions to resist yawning INCREASE the urge to yawn.
"Second, the propensity for contagious yawning was shown to be strongly predicted by individual variability in TMS measures of cortical motor excitability and physiological inhibition recorded from the hand area of the primary motor cortex". This is a common form of echophenomenon, which is a fancy word for automatically mimicking another person's actions or words.
Jackson said the findings could have wider uses. They focused on the motor cortex, since it's involved in planning and movement.
North Korea claims to have built advanced hydrogen bomb
North Korea is believed to have conducted a test after a magnitude 5.7 natural disaster was detected earlier Sunday. One blast could knock out power and communications over hundreds or even thousands of kilometers, the report said.
Study co-author Stephen Jackson, the professor of cognitive neuroscience, the University of Nottingham, added: "If we can understand how alterations in cortical excitability give rise to neural disorders we can potentially reverse them".
To test out their theory, the team then stimulated the motor cortex through TMS and found that it would artificially increase participant's propensity for contagious yawning.
Echophenomena is also caused due to various clinical conditions associated with raised cortical excitability and reduced physiological inhibition like dementia, epilespsy, autism and Tourette syndrome. The participants were told to either try to stop themselves from yawning or just let it happen. "In Tourette's, if we could reduce the excitability we might reduce the ticks and that's what we are working on", Prof Jackson said. The findings have led scientists to look for personalised TMS treatments which could help to "modulate imbalances in the brain networks".
If you're in school, the safest bet is probably to be inconspicuous about it.