If you’ve ever found yourself making silly mistakes, such as putting the milk in the cupboard and the cereal in the refrigerator, a region of your brain may have been taking a little nap.
Researchers at the University of Wisconsin-Madison recently found that some nerve cells in a sleep-deprived brain can briefly go “off line,” into a sleep-like state, while the rest of the brain appears awake. As reported in a recent issue of Nature, the researchers studied the electroencephalogram (EEG) measurements of rats that were kept awake for prolonged periods.
“Even before you feel fatigued, there are signs in the brain that you should stop certain activities that may require alertness,” said Dr. Chiara Cirelli, professor of psychiatry at the School of Medicine and Public Health. “Specific groups of neurons may be falling asleep, with negative consequences on performance.”
“We know that when we are sleepy, we make mistakes, our attention wanders and our vigilance goes down,” Cirelli said. “We have seen with EEGs that even while we are awake, we can experience short periods of ‘micro sleep.’”
Cirelli said such “micro sleep” periods were believed to be the cause when people fall asleep while driving, but the new research found that even before that stage, brains are already showing sleep-like activity that impairs them.