Sleep is nature's way to help your brain reset, relax

“Why do people like to sleep?' asked a camper at Mundelein High School's summer STEAM camp.

You're not dreaming if you think you can get by on just a few hours of sleep.

Experts no longer think there is a set amount of time required for adequate sleep, according to Dr. Kenneth Polin, a pediatrician who sees patients at Ann & Robert H. Lurie Children's Hospital in Chicago and Town & Country Pediatrics in Chicago and Glenview.

“Even children may not need the standard average of sleep time. A noncrabby child who's not falling asleep at inappropriate times may have slept enough,” Polin said. “Parents shouldn't get frustrated by a particular number of sleep hours needed.”

Nodding off to sleep typically happens when it's dark outside. Sleep patterns for most people seem to follow the sun's 24-hour cycle, called circadian rhythm, prompting sleepy heads to rise with the sunlight and hit the hay at night when it's dark.

This cycle continues even when there is no sun.

“There was a study where people went into a cave without light,” Polin said. They woke in morning hours as if the sun were up and rested around the same time as evening.

“They followed the normal circadian rhythm,” he said.

All mammals sleep, although there are quite a few that catch winks in the daytime so they can prowl at night. A few super-efficient snoozers use only half their brain in the sleep state, like dolphins, what scientists call unihemispheric slow wave sleep. Even babies inside the womb sleep — a lot.

“People like to sleep because sleep is when the brain relaxes and resets itself. There's a lot of information coming in during the day and sleep allows the brain to organize,” Polin said.

A sleep cycle has four sleep stages that are repeated a few times during a night's sleep. The cycle lasts about 90 to 110 minutes. Stage 1 and 2 transition the brain from wakefulness to the big event — deep sleep and REM or rapid eye movement. The length of time for REM expands with each successive cycle. During REM, when dreams occur, muscles experience paralysis.

Researchers at Stanford University's sleep center, an early leader in sleep research, call sleep one of the greatest mysteries in science. Several theories that attempt to define the purpose of sleep include the concept of brain plasticity, the need for the brain to organize after a day's activities. Researchers point to important body functions that continue operating during sleep — cell restoration, tissue repair, protein synthesis and the production of growth hormones.

Life can be a nightmare without sleep; the body's immune system can become very weak and in rare instances, lack of sleep can cause death.

Polin offers this advice for the best way to get a good night's sleep, “Adjust the environment to limit noise and bright lights. Don't rev up your brain before sleep by eating, watching TV or playing video games. Use your bed for sleep and develop good sleep hygiene.”

Check it out

The Fremont Public Library in Mundelein suggests these titles on sleep:

• “All About Sleep From A to ZZZZ,” by Elaine Scott

• “101 questions About Sleep and Dreams That Kept You Awake Nights — Until Now,” by Faith Hickman Brynie

• “Sleep and Dreaming,” by Marvin Rosen

• “The Way We Work: Getting to Know the Amazing Human Body,” by David Macaulay