Stickgold said he believes that when students sleep, their memories are consolidated and reorganized so that information stays with them in the long term.

Stickgold also said that while most people need eight to eight and a half hours of sleep to feel well-rested, the time can vary from individual to individual--though few people get as much as they should.

"Your body tells you how much sleep you need, and we all ignore it," Stickgold said. "The test I tell people is, if you drink coffee before 10 a.m., then you're just self-medicating."

Stickgold said that in his experience, Harvard students--with difficult classes, problem sets and midterms--are particularly prone to ignoring their need for sleep. He blamed Harvard for perpetuating the nasty habit.

"Shame on Harvard for trying to put in another meal at midnight instead of backing off on the workload," he said.

Some students, like Valentina M. Perez '03, have already learned the hard way. Perez said she averaged three hours of sleep a night her first year but then changed her habits; she now clocks in at least seven hours of sleep per night.

"I've already learned that when you sleep more, you do better," Perez said. "The key is time management--sleep definitely makes a difference on your output."