Why yawning is contagious? Read on to find out
It often occurs when you’re tired, bored, or even after seeing someone else yawn. This reflex involves various muscles in the ...
来自MSN2 个月
Does yawning mean our brains aren’t getting enough oxygen?
One theory is that by moving the muscles in the face and neck, yawning stimulates the carotid arteries in the neck, increasing blood flow to the brain and waking it up. Additionally, a 2012 study ...