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Lack of sleep leads to brain power failure
(Agencies)
Updated: 2008-05-23 10:48 BEIJING -- Take away sleep for just one night and the brain becomes unstable and liable to sudden shutdowns similar to a power failure, researchers said on Tuesday. "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. "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." The findings suggest 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," 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. He said the lapses seem to suggest that loss of sleep renders the brain incapable of fully fending off the involuntary drive to sleep. He said the study makes it clear how dangerous sleep deprivation can be while driving on the highway, when even a four-second lapse could lead to a major accident. |
