The reason we blink Most of the time it's so our brains can switch off
When we blink, our brains goes into idle mode where thoughts wander freely, say Japanese researchers
These mental breaks can last anywhere from a split second to a few seconds before attention is fully restored Most of us take between 15 and 20 such moments of downtime per MINUTE
19:00 GMT, 2 January 2013
19:01 GMT, 2 January 2013
We spend around 10 per cent of our waking hours with our eyes shut.
And while it's commonly thought that we blink to keep our eyes lubricated, it seems a lot of the time it's because our brains need a little nap.
New research suggests that the human brain uses that tiny moment of shut-eye to power down.
Blink and you'll miss it: Scientists find that blinking is a chance for our brains to power down
Researchers from Japan's Osaka University found that the mental break can last anywhere from a split second to a few seconds before attention is fully restored.
Scans that track the ebb and flow of blood within the brain revealed that regions associated with paying close attention momentarily go offline.
The brain then goes into a 'default mode network', or idle setting.
The same setting is engaged when our attention is not required by a cognitive task such as reading or speaking and our thoughts wander freely.
Mini nap: blinking allows the brain to go into idle mode
During this mode we tend to contemplate
our feelings; we wonder what a friend meant by a recent comment; we
consider something we did last week, or imagine what we'll do tomorrow.
While listening to another person or
reading, that usually comes at the end of a sentence and while watching a
film, we're most likely to blink when an actor leaves the scene
or when the camera shifts.
Most of us take between 15 and 20 such moments of downtime per minute.
The new research, published this week in the journal Proceedings of the National Academies of Science, studied 20 healthy young subjects in a brain scanner as they watched snippets from the British comedy Mr. Bean.
When subjects blinked, the researchers detected a momentary stand-down within the brain's visual cortex and somatosensory cortex — both involved with processing visual stimuli – and in areas that govern attention.
Separate studies on blinking have shown that while telling a lie, people have been found to blink less.
In the seconds after telling a lie, however, the liar will blink far more frequently than a truth-teller.