Posted on 07/25/2005 1:40:31 PM PDT by Cincinatus' Wife
Parts of the brain are temporarily "switched off" when we blink, scientists have found.
Researchers from University College London found that the brain actively shuts down parts of the visual system for every blink - even if light is still entering the eyes.
This could explain why people do not notice their own blinking.
The study used a specially-designed device to study the effects of blinking on the brain.
The device, made with fibre optic cable, was placed in the mouths of volunteers who were wearing light proof goggles and lying in a functional magnetic resonance imaging (fMRI) brain scanner.
The optical fibre lit up the eyeballs through the roof of the mouth using a strong light - making the head glow red and meaning that the light falling on the retina in the eye remained constant even when the participants blinked.
Scientists were then able to measure the effects of blinking on brain activity independently of the effect of eyelid closure on light entering the eye.
The researchers found that blinking suppressed brain activity in the visual cortex and other areas of the brain - known as parietal and prefrontal - which are usually activated when people become conscious of visual events or objects in the outside world.
Davina Bristow, from UCL's Institute of Neurology, said: "Blinking is necessary to keep the surfaces of the eyes moist.
"Most people blink around 15 times a minute and a blink lasts on average 100-150 milliseconds, which means that overall we spend at least nine days per year blinking.
"We would immediately notice if the outside world suddenly went dark, especially if it was happening every few seconds.
"But we are rarely aware of our blinks, even though they cause a similar reduction in the amount of light entering the eye, and this gives us an uninterrupted view of the world.
"Transiently suppressing the brain areas involved in visual awareness during blinks may be a neural mechanism for preventing the brain from becoming aware of the eyelid sweeping down over the pupil during a blink and the world going dark."
The research, published in the latest issue of Current Biology, was funded by the Wellcome Trust.
Nancy Pelosi PING!
Apparently you can consciously override this shutoff mechanism. I certainly can see myself blink when I want to.
Perhaps this explains why those people whose eyelids "flutter" every so often -- we all know them -- seem so freakin' stoopid. :-)
There's a joke in there somewhere.
That explains most of the lyrics to any song by Blink182.
Well, one might ask if there is a similar effect on the human brain when their mouth opens.
I guess I'm semi-permanently in a state of blink.
Yeah, but NOW I can't stop paying attention to 'em... dammit...
Somebody please pull this thread before others get trapped in the same dilemma.
That is really creepy.
LOL! Me too. It's driving me nuts.
Blech! Why are you trying to make ME blink????? ;)
But we can think with our eyes closed, so go figure.
LOL
Ted Kennedy gags, falls into a depression, until he re-reads the headline...
She is blinking. She's had so many facelifts, her eyes are actually on the back of her head. The eyes in the picture are painted on.
I think (must not be blinking) it is a lousy headline.
I alternate my blinking, left then right. That way I'm never out of touch...
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