A new study from the University of New South Wales suggests that yawning may play a crucial role in cleaning the brain by influencing the flow of cerebrospinal fluid (CSF). This finding challenges previous assumptions about this common behavior.
The research involved 22 healthy participants who underwent MRI scans while yawning and deep breathing. Results showed that yawning triggers a movement of CSF away from the brain, unlike deep breathing, which sends CSF into the brain.
Both yawning and deep breathing increased blood flow leaving the brain. Notably, yawning appears to help clear waste from the brain, particularly close to bedtime. This could have implications for understanding neurodegenerative diseases.
Cerebrospinal fluid is essential for cushioning the brain and transporting nutrients and waste. Adam Martinac, one of the researchers, stated, “Yawning remains very mysterious…” He noted that each person has unique yawning patterns, indicating a central pattern generator for this behavior.
Key findings:
- Yawning causes a 30% increase in carotid arterial blood flow into the brain.
- The study found that yawning may assist in cleaning brain fluid.
- Yawning is seen across many species and tends to be contagious.
The exact impact of this shift in CSF flow during yawning is not yet clear. The link between yawning and waste clearance from the brain is still under investigation. Further research is expected to explore these connections.