Science Says: This is Why We Blink

By Wesley Fenlon

Every time you blink, your brain takes a quick breather to help it focus on the outside world.

Like breathing, blinking is one of those reflexes we don't notice in our day-to-day lives. It's just something we do thousands of times a day to keep our bodies functioning normally. Consciously pay attention to how often you're blinking--an average of 15 or 20 times per minute--and you'll be distracted by how often your eyelids flick up and down. You'll lose track of what you're doing and become preoccupied with the blink. As reported by Smithsonian Mag, there's a solid scientific explanation here--blinking isn't just about the eyes.

Scientists know that we blink more often than necessary to keep our eyes moist and protect them from airborne hazards. But no one has known why our eyelids are on constant overdrive--it's an innate reflex we simply don't understand. Or at least, didn't understand--a new Japanese study might've cracked the case. Their theory: We blink to focus.

The research paper posits that people blink at predictable times rather than randomly. We blink after we finish reading a sentence and before starting the next. A group of people will predictably blink during the slowest moments of a video. To test the theory that we momentarily close our eyes to rest our brains and focus on the task at hand, the researchers put their volunteers in fMRI machines and monitored their brain activity as they watched Mr. Bean.

And the results:

"We show that while viewing videos, cortical activity momentarily decreases in the dorsal attention network after blink onset but increases in the default-mode network implicated in internal processing. In contrast, physical blackouts of the video do not elicit such reciprocal changes in brain networks. The results suggest that eyeblinks are actively involved in the process of attentional disengagement during a cognitive behavior by momentarily activating the default-mode network while deactivating the dorsal attention network."

The default-mode network portions of the brain are active when the brain is at rest. Since blacking out the video had no similar effect, the blinking reflex obviously affects these parts of the brain. The study may not apply to every activity in our daily lives, but it's still an insightful breakthrough. Every blink is a quick message to your brain to take a well-deserved nap. Thanks, eyelids.

Image credit: Jamie Beck and Kevin Burg via Beautiful Life