Studies show that sleep deprivation impairs the brain's ability to learn and remember information.

Scientists believe that when the patterns of electrical and chemical activity that occur during sleep are interrupted, the brain’s ability to function normally is impeded.

For example, the brain regions that are active in a well-rested person who is working through an arithmetic problem are less responsive in a sleep-deprived person.

In one study, a group of sleepy people made significantly more math errors than a group of similarly-educated people with adequate rest.

Other studies show that the temporal lobe, an area of the brain that's involved in language processing, is activated during verbal learning in rested people but not in sleep-deprived people.

So students who don't get a full night's rest are more likely to have trouble concentrating and learning in school.

the five to 10 hours following learning are crucial for memory consolidation; sleep deprivation during this time period can impair the brain's ability to "file away" new information.

This means all-night cramming sessions before exams may be less effective than studying up till normal bedtime and getting a full night's sleep.