“Why do our eyes water when we yawn?” According to popular opinion, it is because you are tired and you miss your bed, which is why you begin to tear up. Don’t believe us? Well, you shouldn’t.
As much as that rationale seems right (on an emotional level), there is complete science behind the question ‘why do our eyes water when we yawn?’.
To understand this phenomenon, you will first need to understand tear-anatomy. Did you know there are three types of tears that your eyes shed?
1. Emotional Tears: Released upon experiencing intense emotions
2. Reflexive Tears: They serve to remove irritants and contaminants from the eyes like dust, dirt, etc.
3. Basal Tears: They are produced naturally throughout the day to lubricate the eyes.
But our question was :
Why do our eyes water when we yawn?
It is these basal tears that are responsible for the tears when you yawn.
Two components of the face are primarily responsible for our eyes to water when we yawn,
• Facial muscles
• Lacrimal glands
Lacrimal glands are glands that are placed beneath our upper eyelids just below the eyebrow bone.
They produce watery component to our eyes’ own natural tears throughout the day to keep the surface of our eyes coated and moisturized. Thus, our eyes remain moist throughout the day because of the functioning of lacrimal glands (This is also the reason why our eyes look glossy)
There are 43 muscles in the face itself that work together to help us emote. When we yawn, the facial muscles around our eyes begin to tighten. This exerts pressure on the lacrimal glands and squeezes them a little.
In response, the lacrimal glands may release a little quantity of water which had been stored to release later.
Basal tears typically flow diagonally across the eyes and collect in a structure on the opposite corner of the eye called punctum.
But when we yawn, this water has no passage to get absorbed, and hence it falls out of the eyes, which is why it appears as if we are shedding tears.
Now if you shed a tear or two while yawning, don’t feel like it’s a ‘miss you’ call from your bed; it’s just a natural reaction to feeling tired.
And if the next time somebody asks you, ”why do our eyes water when we yawn?”, don’t shy away from sharing the knowledge!
Contagious yawning is triggered involuntarily when we observe another person yawn, it is a common form of Echophenomena
The Research findings showed that our urge to yawn is increased if we are instructed to resist yawning
Echophenomena isn’t just a human trait, it is found in chimpanzees and dogs too
New York, USA, September 3, 2017: Ever wondered why even if we are not tired, we yawn if someone else does? Why is yawning so contagious?
It is because the human propensity for contagious yawning is triggered automatically by primitive reflexes in a brain area responsible for motor function, a research suggests.
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).
The Research findings showed that our urge to yawn is increased if we are instructed to resist yawning. And 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.
“This research has shown that the ‘urge’ is increased by trying to stop yourself. 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.
“The findings may be important in understanding the association between motor excitability and the occurrence of Echophenomena in a wide range of conditions linked to increased cortical excitability and/or decreased physiological inhibition such as epilepsy, dementia, autism, and Tourette syndrome,” added Stephen Jackson, a Professor at the University.
For the study, published in the journal Current Biology, the team used transcranial magnetic stimulation (TMS) to analyze volunteers who viewed video clips showing someone else yawning and were instructed to either resist yawning or to allow themselves to yawn.
“If we can understand how alterations in cortical excitability give rise to neural disorders we can potentially reverse them. We are looking for potential non-drug, personalized treatments, using TMS that might be effective in modulating imbalances in the brain networks,” Jackson said.
Echophenomena isn’t just a human trait, it is found in chimpanzees and dogs too. (IANS)