Feeling tired? Even if we aren't tired, why do we yawn if someone else does? Experts at the University of Nottingham have published research that suggests the human propensity for contagious yawning is triggered automatically by primitive reflexes in the primary motor cortex an area of the brain responsible for motor function.
Their study 'A neural basis for contagious yawning' has been published in the academic journal Current Biology. It is another stage in their research into the underlying biology of neuropsychiatric disorders and their search for new methods of treatment.
Their latest findings show that our ability to resist yawning when someone else near us yawns is limited. And our urge to yawn is increased if we are instructed to resist yawning. But, no matter how hard we try to stifle a yawn, it might change how we yawn but it won't alter our propensity to yawn. Importantly, they have discovered that the urge to yawn our propensity for contagious yawning is individual to each one of us.
Echophenomena isn't just a human trait
Contagious yawning is triggered involuntarily when we observe another person yawn it is a common form of echophenomena the automatic imitation of another's words (echolalia) or actions (echopraxia). And it's not just humans who have a propensity for contagious yawning chimpanzees and dogs do it too.
Echophenomena can also be seen in a wide range of clinical conditions linked to increased cortical excitability and/or decreased physiological inhibition such as epilespsy, dementia, autism and Tourette syndrome.
The neural basis for contagious yawning
The neural basis for echophenomena is unknown. To test the link between motor excitability and the neural basis for contagious yawning the Nottingham research team used transcranial magnetic stimulation (TMS). They recruited 36 adults to help with their study. These volunteers viewed video clips showing someone else yawning and were instructed to either resist yawning or to allow themselves to yawn.