Yet, strangely enough, until recently, nobody really knew why.
The authors of a new study think they've found the reason: when sleep deprived, our brains produce significantly fewer new connections between neurons.
The study in question involved training mice to walk on top of a rotating rod. Mice that were sleep deprived produced far fewer connections between neurons. In other words, they weren't processing what they were learning as well as the mice that were sleeping.
By disrupting different stages of sleep, researchers discovered that slow-wave sleep (also known as deep sleep) was the most important stage of sleep for memory formation.
Interestingly, researchers also found that extra training didn't make up for the negative effects of sleep deprivation.
Mice that received an hour's training followed by sleep still performed significantly better than sleep deprived mice that received 3 hours of training.
Last updated: June 23, 2014