Here are two interesting links to an article in New York magazine by Po Bronson and Ashley Merrymon.
Full article: “Can a Lack of Sleep Set Back Your Child’s Cognitive Abilities?”
“Dr. Matthew Walker of UC Berkeley explains that during sleep, the brain shifts what it learned that day to more efficient storage regions of the brain. Each stage of sleep plays a unique role in capturing memories. For example, studying a foreign language requires learning vocabulary, auditory memory of new sounds, and motor skills to correctly enunciate new words. The vocabulary is synthesized by the hippocampus early in the night during “slow-wave sleep,” a deep slumber without dreams. The motor skills of enunciation are processed during Stage 2 non-rem sleep, and the auditory memories are encoded across all stages. Memories that are emotionally laden get processed during R.E.M. sleep. The more you learned during the day, the more you need to sleep that night.”
“Sleep is a biological imperative for every species on Earth. But humans alone try to resist its pull. Instead, we see sleep not as a physical need but a statement of character. It’s considered a sign of weakness to admit fatigue, and it’s a sign of strength to refuse to succumb to slumber. Sleep is for wusses.
“But perhaps we are blind to the toll it is taking on us. The University of Pennsylvania’s David Dinges did an experiment shortening adults’ sleep to six hours a night. After two weeks, they reported they were doing okay. Yet on a battery of tests, they proved to be just as impaired as someone who has stayed awake for 24 hours straight.“