I. CAN’T. STOP. YAWNING.
And I have no one to blame but myself. After all, I know damn well that writing a bit over yawning and trolling through hundreds of pictures of people yawning will inevitably keep inducing the same ugly o-like expression on my face.
Well, as it turns out, contagious yawning is a form of echophenomena, or the automatic imitation of someone else’s words or actions.
Okay, but why is automatically imitating someone a thing?
Well, the neural basis behind the phenomenon has sorta-kinda eluded psychologists for some time now, but it tends to regularly be linked to over-excitement in the cortical motor areas in our brains and/or our mirror-neuron systems.
A new study coming out of the University of Nottingham just explored the topic a little further than you or I, and seems to have a way better idea as to what’s causing the brain to induce this undesirable phenomenon, so let’s check it out.
Using transcranial magnetic stimulation (TMS), a team of researchers first measured cortical excitability and physiological inhibition across 36 healthy adults (n = 36), and then used the results to predict the participant’s individual propensity for contagious yawning.
rats humans watched video clips of other people yawning, and in separate intervals were told to either resist yawning or allow theirselves to yawn unrestrained.
Throughout the process, the participants were recorded on video and tracked as to how many times they yawned, or had a stifled yawn, and the intensity of each participant’s perceived urge to yawn was recorded and measured using a slider device operated by his or her right pointer finger. To make sure the participants paid attention to the videos, they were required to answer a question about the corresponding video after each view.
During the third and fourth trials of the experiment, excitatory non-invasive electrical brain stimulation known as anodal transcranial direct current stimulation (tDCS) and/or transcranial random noise stimulation (tRNS) was delivered to the cortical SMA region of half of the participants’ brains, and faux stimulation was given to the other half.
Researchers were able to use TMS to not only quantify the motor cortical excitability and physiological inhibition across participants, but to also accurately predict the propensity of each person to yawn contagiously.
Furthermore, telling the participants to resist yawning actually increased their urge to yawn and altered how their yawns were expressed, either stifled or full, but didn’t affect the propensity to contagiously yawn.
Overall, the brain stimulation (from tDCS and tRNS) significantly increased the urge to yawn across participants, and may end up being particularly important in further understanding the association between motor excitability and echophenomena.
Because echophenomena can be observed across a myriad of clinical conditions like autism, dementia, epilepsy, and Tourette syndrome, understanding this relationship may be the first step in relieving suffering.
*This study is just one in many toward uncovering the underlying biology of neuropsychiatric disorders, as well as some possible new methods for treatment.