How much sleep do children need? Research: In a Rhode Island laboratory, tests are under way to determine what makes the biological clocks of youngsters tick.

September 06, 1998|By Felice J. Freyer | Felice J. Freyer,PROVIDENCE JOURNAL

PROVIDENCE, R.I. - It's midmorning and the three youngsters, all preteens, have just finished dinner. Now they are in their dim bedrooms, playing video games. In a few hours - midafternoon in our world - they'll knock off for the "night."

Their quarters have no windows. They haven't seen the sun or their parents' faces in more than two weeks. They haven't a clue as to what time it is. And, by all accounts, they're having a great time.

Welcome to the Bradley Sleep Lab, where sleep researcher Mary Carskadon seeks to unravel the biological secrets of children's sleep.

Carskadon is widely known as the Brown University professor who is urging school districts to start high school later in the day for the sake of teen-agers' health. She discovered that adolescents like to stay up late and sleep late, not merely to annoy their parents and teachers, but because their changing bodies command it.

It's no trivial matter: Faced with earlier school starting times, teen-agers arrive at school with fogbound brains ill-prepared to learn. Lack of sleep has been linked with poor school performance and difficulty regulating mood and emotion.

Officially called the Biological Rhythms and Sleep Research Laboratory, Carskadon's home base is a white cottage on the bucolic Butler Hospital campus, where the lab has been since 1990. The children's "sleep camp" at first glance looks like anyone's "down cellar," with paneled walls, a couch and table. But the light is low, and as you walk around the corner you see a wall of electronic equipment reminiscent of Mission Control.

On a small video screen, a boy can be seen sitting up in bed, a computer in front of him. He cheers, pumping his arms in the air. Then a voice over the intercom asks the kids to stop their games to do a performance test, also on the computer. Their memory, alertness and response time will be measured, and while they perform the tasks, electrodes attached to their scalps measure brain waves.

The children, who range in age from 9 to 13, cannot be interviewed or even know there are visitors in the lab. Outsiders might inadvertently tip them off about the real time, and the stimulation will affect their biological responses, distorting the readings.

Most of the children in the current study have participated in shorter projects at the sleep lab, so they have an idea what to expect. They were initially recruited through their schools and newspaper ads. Carskadon looks for kids who are healthy and normal, and bright enough to respond well to researchers' questions.

They each earn $300 and a $500 savings bond for their trouble.

In her basement lab, with a team of 16 college students working as research apprentices, Carskadon seeks to measure the children's "internal day length" - how long they would stay awake and how long they would sleep if they had no outside influences. Every species has an internal biological clock that runs slightly askew from the passage of night and day. Through exposure to light and other cues, animals become synchronized to the outside world; their internal clocks adjust to the earth's day. To determine the internal clock's pace, you have to close off the outside world. Hence, the basement.

With close attention from the research assistants, the kids play games, watch movies and chew cotton balls every half-hour or so to give saliva samples (measuring levels of melatonin, a hormone that induces sleepiness). Their heads are festooned with electrodes that get hooked up for readings when they sleep or do performance tests.

Carskadon is testing the theory that youngsters on the cusp of adolescence gradually become night owls because their internal days lengthen. When teen-agers are required to start school at 7:30 a.m., Carskadon says, "These kids are in shift-work conditions. They're being asked to perform at times when their biology is out of sync with expectations.

"This study helps us link the sleep issue to psychological and medical health issues," she continues. "This is an important service to teen-agers. It keeps them from being [seen as] bad guys."

Pub Date: 9/06/98

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