Written by Rita Jenkins| 26 July, 2005  20:01 GMT
 Research shows that areas of the brain actually shut down with each blink of the eye.
The expression, "Don't blink or you In the 1980s, scientists discovered that visual sensitivity begins decreasing
immediately before a blink, but the brain mechanisms underlying this process
have remained unclear until now.
In the UCL study, researchers devised a clever way to monitor the brain's
activity, under conditions in which the amount of light received by the eye was
constant, regardless of blinking.
This was achieved by placing a light-emitting optical fiber in the mouth of
volunteers who were wearing light-blocking goggles. The light was bright enough
to reach the retina by passing through the roof of the mouth.
The Blink Is the Link
The researchers then performed magnetic resonance imaging, or MRI, on the
volunteers, to see how the brain would react when light was uninterrupted during
blinking.
It was discovered that brain activity in areas that are active when people
become conscious of visual events or objects in the outside world were
suppressed during blinking -- even though the light falling onto the retina
remained constant throughout the blink.
The UCL scientists conclude that the brain's ability to shut down during
blinking is a neural mechanism that protects us from the constant distraction
and discontinuity that otherwise would result from the frequent mini-blackouts.
Lost in the Blink of an Eye
The average person blinks about 15 times per minute. So, even though the
mini-blackouts are instantaneous, they add up to about nine days per year -- or
up to one or two years of an average lifespan.
The years are literally lost in the blink of an eye. |