An intriguing study has highlighted the effects of yawning on the human brain.
At the University of New South Wales in Australia, researchers conducted MRI scans on the heads and necks of 22 healthy individuals to observe the effects of actions such as yawning and deep breathing.
Their findings regarding yawning were particularly noteworthy, as they diverged from their initial expectations.
The Cleveland Clinic mentions several theories regarding the reasons for yawning.
One theory suggests that yawning helps to ‘wake up’ the brain, with fatigue and boredom being potential triggers.
They clarify: “Boredom happens when the main source of stimulation in your environment is no longer able to keep your attention. This triggers drowsiness by stimulating your body’s sleep-signaling system.”
Researchers also propose that yawning might serve as an automatic response to cool the brain, influenced by changes in blood flow due to air intake.
Social factors are considered as well, with the ‘communication hypothesis’ suggesting that yawning after observing someone else yawn might be a way to connect or express boredom.
But how do these findings translate into MRI imagery?
Upon analyzing the MRI scans, the research team discovered that yawning and deep breathing did not produce the same results, as initially thought.
In the process of yawning, cerebrospinal fluid (CSF) moves away from the brain, unlike during deep breathing.
“The yawn was triggering a movement of the CSF in the opposite direction than during a deep breath,” neuroscientist Adam Martinac shared with New Scientist.
“And we’re just sitting there like, whoa, we definitely didn’t expect that.”
Cerebrospinal fluid is a clear liquid that provides cushioning and nourishment to the brain and spinal cord.
The distinct nature of yawning compared to deep breathing indicates it might play a more significant role in brain function than previously understood.
This supports the hypothesis that yawning helps in cooling the brain.
While exploring similarities between deep breaths and yawning, researchers noted that both actions enhance the flow of blood leaving the brain.
Each participant exhibited unique yawning patterns. Researchers noted: “This flexibility might account for the variations in inter-participant yawning patterns while still maintaining a recognizable, individual-specific pattern; and implies that the patterns of yawning are not learned but are an innate aspect of neurological programming.”