At the University of Pennsylvania School of Medicine
, David Dinge is studying how lack of sleep affects ones activities. He is studying how lack of sleep over time affects the brain and to find out how much sleep is really necessary to get back on track. In particular, some people are more affected than others when it comes to chronic sleep deprivation.
In Dinges study, volunteers are limited to 4 hours of sleep a night for 5 nights, and then allowed to sleep for up to 10 hours for 2 days.
In her article entitled “Dying to Sleep” published in Science News
in October 2009 author Tina Hesman Saey discusses Dinges study.
A volunteer named Heather is behind the wheel in a driving simulator. She has electrodes taped to her head. In this study Heather has gotten only 4 hours of sleep every night for the last 4 nights. She is in a car simulator driving on make believe roads and highways, sharing the road with truckers, bright lights and zig zagging roads. She states “ My limbs feel heavy”. Saey reports that the electrodes on Healthers head are monitoring her brain waves and eye movements so that researches can detect even brief bouts of sleep. Heather has reported feeling light headed and dizzy- and yet she has’nt nodded off and tests show that her driving has not affected by lack of sleep.
Saey reports that the tests in Dinges lab have shown how severly most people’s performance of daily activities can deteriorate with sleep loss. Heather may be one of the few people whose brain is not adversely affected with chronic sleep loss. By looking at Heathers genes, researches can then develop drugs that affect those genes and help ordinary people resist making mistakes after chronic sleep deprivation.
Another volunteer, James who is an architecture student, studys all night especially at the end of the term. He is referred to as a "short sleeper". He functions normally on short amounts of sleep. When tested after sleep deprivation he smashes his vehicle into the back of a truck.
Dinges says that many short sleepers are convinced that they function well on less sleep. He has noticed in his study that most people do not predict how well they will perform after sleep deprivation. Dinges has also found that “some people fall apart after missing just a few hours of sleep”. Other shows a slow steady decline in their ability to remain awake and clear. Other people like Heather, is categorizes as “type 1s”- these people’s performance does not change with 5 days of restricted sleep. According to Dinges, “people are walking around with grossly different brain activity profiles”.
So whats the magic number of how many hours of sleep one should get every night? According to the author, Saey, her research has shown that the “normal” range includes 6 to 10 hours of sleep per night, depending on the person. In her research she further highlights that “sleeping about 7-8 hours carries the least risk of obesity, diabetes, heart disease and other illnesses”.
The National Sleep Foundation conducts research on people’s sleep habits. Their research shows that overall, people are just getting less sleep in general. Here some interesting facts they have found:
In 2009, 20% of those surveyed said they slept less than 6 hours on weeknights, compared with an earlier study in 1998 which was 12%
In 2009, respondents reported sleeping 7.1 hours on weekends, down from an average of 7.8 hours in 1998>
So as this study shows even if you think you will be functioning at 100% with a lack of sleep, think again. Sleep is too important to be taken lightly. Sleep, along with food, water, and exercise must be a staple in your everyday life.