Sleepy brains prone to sudden shutdowns
Pastor Dale Morgan
*Sleepy brains prone to sudden shutdowns*
By Julie Steenhuysen in Chicago
May 21, 2008 09:14am
Article from: Reuters
BEING deprived of sleep even for one night makes the brain unstable and
prone to sudden shutdowns akin to a power failure - brief lapses that
hover between sleep and wakefulness, researchers say.
"It's as though it is both asleep and awake and they are switching
between each other very rapidly," said David Dinges of the University of
Pennsylvania School of Medicine, whose study appears in the Journal of
Neuroscience.
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"Imagine you are sitting in a room watching a movie with the lights on.
In a stable brain, the lights stay on all the time. In a sleepy brain,
the lights suddenly go off," Mr Dinges said in a telephone interview.
The findings suggest that people who are sleep-deprived alternate
between periods of near-normal brain function and dramatic lapses in
attention and visual processing.
"This involves more structures changing than we've ever seen before, but
changing just during these lapses," Mr Dinges said.
He and colleagues did brain imaging studies on 24 adults who performed
simple tasks involving visual attention when they were well rested and
when they had missed a night's sleep.
The researchers used a type of brain imaging known as functional
magnetic resonance imaging, or fMRI, which measures blood flow in the brain.
They found significant, momentary lapses in several areas of the brain,
which seemed to frequently falter when the people were deprived of
sleep, but not when these same people were well rested.
"These people are not lying in bed. They are sitting up doing a task
they learned and they are working very hard at doing their best," Mr
Dinges said.
He said the lapses seemed to suggest that loss of sleep rendered the
brain incapable of fully fending off the involuntary drive to sleep.
He said the study made it clear how dangerous sleep deprivation could be
while driving on the highway, when even a four-second lapse could lead
to a major accident.
"These are not just academic interests," he said