Blinking Allows the Brain to Rest, New Study Finds

Sharon Moore January 02, 2013

You may not notice it but on average, your eyes blink 22 times per minute. But do you ever wonder why it happens? In a new research, scientists discovered that blinking is the brain’s way to experience ‘wakeful rest’.

As many of us know, blinking is the body’s way to lubricate the eyes. When you blink, your tears spread across your eye so it doesn’t dry out. But a growing body of research indicates that there’s a far more complicated mechanism associated with blinking.

Blink to rest your brain

In a study published in the journal Proceedings of the National Academies of Science, researchers from Osaka University in Japan asked 20 healthy young individuals to watch video clips of the popular British comedy show “Mr. Bean”.

Using an MRI scanner, the researchers checked for any changes in the brains of the subjects as they blink. In an earlier study, the implicit breakpoints in the video clips that triggered eye blinking have already been established so the researchers know exactly when to look for the changes in the brain’s activation process.

The study findings suggest that blinking helps people reset their focus – making it easier to shift their attention from one subject to another.

When the participants blinked, the researchers noticed a quick stand-down in the brain’s default mode network – the visual cortex and somatosensory cortex (the regions involved in attention and in the processing of visual stimuli). The default mode network appears to step up to fill the momentary lapse in attention. After which, attention was restored.

However, it’s possible that the researchers were only seeing such effect because there are no visual stimuli during blinking. To rule out this possibility, the researchers performed another experiment. This time, they inserted about nine 165 milliseconds of blank screen time per minute into the video. During such short periods of time, the subjects’ default mode network did not power up in response even if they blinked their eyes. According to the researchers, it is because they did not recognise a breakpoint in the action. With this, they concluded that blinking is more of a deliberate act rather a response to the absence of stimuli.

Default Mode Network – Brain’s Idle Setting

Years ago, scientists have found that the default mode network is the brain’s ‘idle’ setting. When the brain is not preoccupied with certain functions such as reading, writing or speaking, such network comes alive and thoughts begin to wander freely. In the idle mode, we shift our thoughts from the present to the past and future events, to almost anything.

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