The Science Of Sleep

Lesley Stahl Explores The Latest Findings In Sleep Research

(CBS)  This segment was originally broadcast on March 13, 2008. It was updated on June 12, 2008.

Human beings spend on average one third of our lives asleep. We know we need to sleep, but most of us have never really given a whole lot of thought to why.

Why do we spend seven or eight hours a night immobile and unconscious? What really happens inside our brains and bodies while we're sleeping?

As correspondent Lesley Stahl first reported this spring, it's one of the biggest unanswered questions in all of science, which is why researchers all over the country are doing studies, and coming up with some new, intriguing discoveries.

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"We don't sleep just to rest our tired bodies?" Stahl asks Matthew Walker, the director of the Sleep and Neuroimaging Lab at the University of California, Berkeley.

"Well, that's been one of the long-standing theories. But I think what we're starting to understand is that sleep serves a whole constellation of functions, plural," Walker explains.

One thing that's clear, says Walker, is that sleep is critical. In a series of studies done back in the 1980s, rats were kept awake indefinitely. After just five days, they started dying.

Walker says they started dying from sleep deprivation. "In fact, sleep is as essential as food because they will die just about as quick from food deprivation as sleep deprivation. So, it's that necessary," he says.

And it's not just rats: every animal studied so far needs sleep, from the elephant right down to the fruit fly. But that's as far as the similarities go. Some animals sleep 20 hours a day, others only two or three. And still others sleep with half their brains at a time, all making it hard to figure out what exactly it is about sleep that makes it so essential, and that, in terms of evolution, makes it worth the risks.

"You wonder why we developed this if survival is the whole point. Because you're completely vulnerable when you're lying there," Stahl points out.

"Whatever the function of sleep, or the functions of sleep are, they seem to be so important that evolution is willing to put us in that place of potential danger by losing consciousness. It would be the biggest evolutionary mistake if sleep does not serve some critical function," Walker says.

One of the most exciting new discoveries in the field of sleep research involves learning and memory.

Five college students were subjects in one of Walker's studies, and they had been awake for more than 24 hours. He has found that students like these do 40 percent worse memorizing lists of words after a night without sleep. But he has discovered something far more revolutionary about what happens when we do sleep.

"Sleep, we've been finding, actually can enhance your memories, so that you'll come back the next day even better than where you were the day before," Walker tells Stahl.

To prove it, Walker put Stahl through a test he's given to more than 400 study subjects. Stahl had to type a series of numbers - 4, 1, 3, 2, 4 - over and over again with her left hand, making a new physical memory.

[kids15]

I really enjoyed the topic because the topic is about our every day lives. Millions of americans suffer from not getting enough sleep. For instance americans are in so much stress living in the every day lives we dont realize that not getting enough rest can make the individual sick. A persons body can begin to shut down without a person not even knowing it. We have daily american people working numerous amount of shifts. We have americans working part-time, full-time, eight hour shifts, four days on four days off and so on. When the typical person finally lies down the individual cant go to right to sleep. Their legs might cant keep still and it goes on and on. Inconclusion, if americans could maybe when get the chance to get a couple of hours of rest, they might take advantage of it. I am a Certified Nurses Aide, and I am trying to get into the RN program, and me myself is an an example because of everyday living. If americans could take the time out to think about maybe if something needs to be done if maybe putting it on the back burner or if its not as important as the other errands during the day, then maybe that could be an extra hour in the day to be able to relax and have time for themselves.

[8471nextel]

I find this video very interesting, specially the second part because it can be related to our teenager?s life. It is very important for them to understand the importance of getting enough hours of sleep, learn the consequences of sleep deprivation and to understand the constellation of healthy related issues when not getting enough sleep. We can start from the cognitive, emotional and physical impairment. Many students fell asleep during class for that reason, their levels of academic achievements are greatly affected and their vulnerability to make wrong decision can is also highly increased for the very same reason. Even obesity seems to be somehow related. How about driving at 16 when sleep deprived?.extremely dangerous...
I also believed that videos like this one and others related to sleep are supposed to be shared with students in the classroom, in a sleep awareness week or once a year, mandatory.

[sleepnotebook]

It is truly amazing how the brain works while we sleep. When most think our brain is resting, it turns out that it is more active than when awake at certain times of the night. What I find amazing is how the mind goes through the levels of sleep and goes through the pattern multiple times per night. I have definitely applied the rule that if I ever take a nap, I try to never sleep more than 20 minutes or so, forcing my brain to not dip into the deeper levels of sleep. Check out my blog as I battle with problematic sleep at http://www.sleepnotebook.com

[khristine415]

I suffer from Complex Post-Traumatic Stress Disorder (C-PTSD) and have had trouble with sleep for many years. A lack of sleep during my most troublesome times and symtoms makes the CPTSD worse. This segment was very interesting to me. Lack of sleep can cause a snowball effect with existing mental disorders and mental disorders can also effect sleep. I have found that if I can improve my sleep, or sometimes actually get to sleep and stay asleep, that my symptoms are better and I have an easier time coping with the anxiety and C-PTSD symptoms.

Khristine415

[bealll95]

I''d LOVE to see this study with Paramedics. I have worked as a Paramedic for 14 years now and I have ALWAYS mentioned that the 24 hours with no sleep and treating patients is not only dangerous for the Paramedics, but maybe even fatally dangerous for the patients. Not to mention you have an EMT driving the ambulance with no sleep and using lights and sirens and breaking red lights. How scary is that!?!?!?!

[cbsuser0423]

Is there an address I can write to, to be a part of the sleep deprivation study? During the article on sleep deprivation, one of the clinics said there studies are open to anyone who might want to participate.

[siscokid19]

With all the research being done and verifications as to the severity of loss of clarity, Why is it the armed forces insists on forcing sleep deprivation on our soldiers? Can''t anyone open their eyes to the lasting harm it does to our men? I''m sure there has been programs on this subject but I for one would like to see an update based on the effect to our military in terms of lives lost and lives permanetly destroyed by sleep deprivation. I am sure that if all the "accidents and situations" created by sleep deprivation were classified correctly as a direct or indirect result of sleep deprivation we would all be shocked into action to somehow come up with an alternative for the armed services. I am also sure that unless people know someone in the service and knows their routines they are not aware of how extensive the problem is.
Please help uncover this abuse.

[gavinjohnson-2009]

Strange that you do a story on "the science of sleep" and yet you never mention modafinil. What gives?

http://en.wikipedia.org/wiki/Modafinil

[gavinjohnson-2009]

Strange that you do a story on "the science of sleep" and yet you never mention modafinil. What gives?

http://en.wikipedia.org/wiki/Modafinil

[libarsh]

Although this piece was not specifically aimed at the problems associated with snoring and obstructive sleep apnea (OSA), the health issues related to sleep deprivation are equally applicable to OSA. Snoring, observed episodes of cessation of breathing during sleep, high blood pressure, a shirt collar size of 17 inches in men and 16 inches in women and excessive daytime sleepiness are suggestive of sleep apnea and should be evaluated by a sleep physician.

Treatment options include CPAP (continuous positive air pressure delivered through a tube and nose mask) and oral appliances that maintain the lower jaw in a forward position.

More information is available at www.snoringisntsexy.com and www.quietsleep.com.

Dr. Barsh

(Producers: If you plan to follow this excellent show with one that discusses sleep breathing problems, I would be happy to talk with you about dentistry''s expanding role.)

[libarsh]

Although this piece was not specifically aimed at the problems associated with snoring and obstructive sleep apnea (OSA), the health issues related to sleep deprivation are equally applicable to OSA. Snoring, observed episodes of cessation of breathing during sleep, high blood pressure, a shirt collar size of 17 inches in men and 16 inches in women and excessive daytime sleepiness are suggestive of sleep apnea and should be evaluated by a sleep physician.

Treatment options include CPAP (continuous positive air pressure delivered through a tube and nose mask) and ora appliances that maintain the lower jaw in a forward position.

More information is available at www.snoringisntsexy.com and www.quietsleep.com.

Dr. Barsh

(Producers: If you plan to follow this excellent show with one that discusses sleep breathing problems, I would be happy to talk with you about dentistry''s expanding role.)

[MollyClaire]

I watched the "Science of Sleep" and "And The Happiest Place On Earth Is...". One question was unanswered: How much sleep do the Danes get?

[johnlsmith7]

I once accepted a position as an Operator at the Diablo Canyon Nuclear Powerplant. I was handed a schedule of:
5 days on 2 days off 2nd shift
then 5 days on 2 days off graveyard
then 5 days on 4 days off day shift
I declined the job because of the sleep rotation but can we trust our Nuclear safety to this type of (forced) depravity on the operators?

[p80_mz]

You should do a test of Air Traffic Controllers. Talk about a sleep deprived bunch many of us are working rotating shifts, 10 hour days, 1 day off per week. Add that to the fact that many millions of lives depend on us men and women everyday and it can take a toll on a person. All the tests I saw performed today were nothing in comparison to making split second decisions when two airplanes are hurtling at each other over 500 mph.

[p80_mz]

You should do a test of Air Traffic Controllers. Talk about a sleep deprived bunch many of us are working rotating shifts, 10 hour days, 1 day off per week. Add that to the fact that many millions of lives depend on us men and women everyday and it can take a toll on a person. All the tests I saw performed today were nothing in comparison to making split second decisions when two airplanes are hurtling at each other over 500 mph.

[p80_mz]

You should do a test of Air Traffic Controllers. Talk about a sleep deprived bunch many of us are working rotating shifts, 10 hour days, 1 day off per week. Add that to the fact that many millions of lives depend on us men and women everyday and it can take a toll on a person. All the tests I saw performed today were nothing in comparison to making split second decisions when two airplanes are hurtling at each other over 500 mph.

[p80_mz]

You should do a test of Air Traffic Controllers. Talk about a sleep deprived bunch many of us are working rotating shifts, 10 hour days, 1 day off per week. Add that to the fact that many millions of lives depend on us men and women everyday and it can take a toll on a person. All the tests I saw performed today were nothing in comparison to making split second decisions when two airplanes are hurtling at each other over 500 mph.

[p80_mz]

You should do a test of Air Traffic Controllers. Talk about a sleep deprived bunch many of us are working rotating shifts, 10 hour days, 1 day off per week. Add that to the fact that many millions of lives depend on us men and women everyday and it can take a toll on a person. All the tests I saw performed today were nothing in comparison to making split second decisions when two airplanes are hurtling at each other over 500 mph.

[agstatered]

I have been sleep deprived since I was 17 years old (1982). Life has been miserable. Sleep studies in the late 80s and early 90s showed no sleep "disorder," but that something was wrong because I could not stay awake during the day studies. They wished me luck. During this time, I was constantly exhausted, sleeping 16-18 hrs/day, incapable of retaining information, inable to focus, falling asleep at inappropriate times, CONSTANT cravings for carbohydrates and increased mental instability (severe OCD, anxiety, and paranoia). In 2000 I was diagnosed with Fibromyalgia. The diagnosising doctor told me the first thing he was going to treat was my lack of sleep.
My life changed after that day. My anxiety, paranoia, and OCD decreased greatly & I lost 45 lbs in 10 wks without exercise. My EXTREME cravings for carbohydrates had dropped to a small rumble. My mental stability was much better; life was not as bleak. Every day life was easier to handle and I no longer felt that my life (and mind) was completely out of control.I will probably always be sleep deprived due to the Fibro, especially while in the workforce. I cannot take the nec. dose of sleep meds during the wk because it''s hard to wake up. I go to work tired. To date, I have NEVER said that I have woken up feeling "refreshed."
I think it is so important that people realize how much sleep is necessary for a well-balanced life and I am very happy that this problem is being focused on. Keep up the good work.

[randallk44]

I very much appreciate the depth to which you covered this!!! I am a person who suffers from mental illness and have gotten worse and worse because I am constantly robbed of sleep. My city (Merced) doesn''t adhere to the Noise Abatement laws and have had to fight for years trying to get the police to enforce the law, with little success. I have people driving throughout the neighborhood multiple times a night, honking their horns repeatedly, to wake up immigrant workers. About 10 more times a night waken up by people driving around with stereos at extreme volumes during the night and all hours of the day.

I have tried time and again to move and the same problems. My health has gotten so bad that I am shoved into depressions that last for months now. It has literally been years since I have gotten anything close to a good nights sleep. For me, my art when I can still focus is my only happiness and I tire of endlessly having to fight for my home.

I mean, I can''t even hardly fill out the registration here - and I used to own a computer shop!!! Endless frustration... (sorry).