The research team used MRI to scan<\/a> the heads and necks of 22 healthy participants while they were told to yawn, take deep breaths, stifle yawns, and breathe normally.<\/p>\n Given that yawning and deep breathing<\/a> share similar mechanisms, the researchers expected them to look similar on the scans. Surprisingly, the images revealed a key difference: unlike deep breaths, yawns sent cerebrospinal fluid (CSF) away from the brain.<\/p>\n “The yawn was triggering a movement of the CSF in the opposite direction than during a deep breath,” neuroscientist Adam Martinac told James Woodford at New Scientist<\/a>.<\/p>\n “And we’re just sitting there like, whoa, we definitely didn’t expect that.”<\/p>\n This wasn’t observed in every case, and occurred less often in men, though the researchers caution that this may be due to interference from the scanner itself.<\/p>\n The analysis also revealed that both deep breaths and yawns increased the flow of blood<\/a> leaving the brain, making more room for fresh blood to be pumped in.<\/p>\n Blood flow didn’t change direction with yawns. Yet during its initial stages, carotid arterial blood flow into the brain surges by around a third, providing potential evidence for multiple reasons for the behavior.<\/p>\n In addition, the participants all had unique yawning patterns<\/a> that were closely followed each time they yawned. It’s a sign that we all have our own central pattern generator<\/a> determining how we yawn.<\/p>\n “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,” write<\/a> the researchers in their paper.<\/p>\n The next big question is what all of this means, and why yawns should differ from deep breaths so substantially when it comes to CSF, a fluid that keeps the central nervous system running smoothly<\/a>, delivering nutrients and removing waste.<\/p>\n One possibility raised by the researchers is that yawning has a specific role in cleaning out the brain<\/a>. Another idea is that it’s some kind of brain cooling function in operation.<\/p>\n Yawns do appear to be closely connected to the brain and the central nervous system \u2013 bigger brains typically lead to longer yawns<\/a>, for example, perhaps a nugget of trivia you can share with friends and family the next time you yawn for an extended period of time.<\/p>\n Related: This Article on The Science of Yawning Will Probably Make You Yawn<\/a><\/p>\n Yawning continues to be a rather baffling phenomenon with a largely unclear purpose, despite being a behavior seen in many different species, and which tends to be contagious among people and animals<\/a>.<\/p>\n “Yawning appears to be a highly adaptive behavior and further research into its physiological significance may prove fruitful for understanding central nervous system homeostasis,” write<\/a> the researchers.<\/p>\n![\"Brain](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2026\/02\/StudySection.jpg\")
The study looked at blood and CSF flow in and out of the brain. (Martinac et al., bioRxiv, 2026)<\/p>\n![\"Subscribe](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2026\/02\/Octopus-yellow-final-642x272.jpg\")
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