August 4, 2010
Updated Aug 4, 2010 at 9:07 PM EDT
Have a bad night's sleep? A new study says it can hurt your brain function, even if you get some rest the next night.
Researchers at the University of Pennsylvania School of Medicine found that loss of attention and delayed reaction times added up over time when people got less than four hours of sleep a night.
The brain function improved with more sleep, but researchers found that at least 10 hours of recovery sleep was needed for the sleep-restricted people to match the functional levels of those who were properly rested.
