All animals need sleep, even insects. But as ubiquitous as sleep is, it is still very mysterious. Why we sleep, and why humans need an average of 8 hours specifically, is still a subject under much debate. One of the dominant theories is that sleep is a time when the body repairs itself. We know that growth hormones are released during sleep, and that sleep depravation has many negative effects on the immune system.
Another theory is that long term memory is consolidated during sleep. Sleep researcher Matthew Wilson, of MIT, recently did some fascinating work into dreaming in particular. He recorded the brains of rats as they ran through a maze, noting the mental activity produced. Later, as the rats were sleeping, he saw the same activity, only more rapid and played in reverse, as if the rat’s mind was rewinding a VHS recording of the run through the maze! Dreaming, Wilson asserts, is a form of “mental cleaning”, where the brain determines what memories it should keep and what to throw out.
Another theory may help us understand why all animals sleep, even those without long term memory. Bruce O’Hara, a professor of biology, explains:
“If we accept the premise that all animals sleep, then it looks like there’s something special about neurons, about basic energy requirements. Neurons are among the cells that have highest energy requirements. Our brain, 1 or 2% of our total bodily weight, uses up 20% of our energy; so the brain is the most energy-demanding organ we have,” O’Hara explains. He concludes that energy usage is one very possible function of sleep. Neurons require this loss of consciousness to slow down just enough so they can replenish themselves for normal functioning. “It’s hard to get solid data to support that, but no data I know of refutes the idea.”
So, it seems sleep is a necessary side effect of owning and maintaining a brain.
Needing less sleep, or none at all!
Even so, the mystery of sleep deepens when you find out that some people need much less sleep, and in rare cases people hardly require any sleep at all!
The longest recorded period without sleep is an astounding 33 years, performed by 64 year old Vietnamese man named Thai Ngoc, who claims to have lost his need for sleep after a sickness in the 70’s. Surprisingly, he experiences no ill negative effects from this condition, not even the normal sleep deprivation effects such as fatigue, loss of concentration, and so on. Under normal circumstances, people who lose even a few days of sleep start exhibiting cognitive symptoms usually only present in senior citizens.
Scientists have found a gene that could be responsible for needing less sleep, which they call “Period 3” or the “Clock Gene”. While most humans need an average of 8 hours of sleep, people with specific variants of the Period 3 gene seem need to much less – sometimes as little as 4 hours of sleep a night. Many notable people through history have claimed to need less sleep – Michelangelo, Napoleon, Thomas Edison all claim to have only needed 4 hours of sleep a night. In modern days, Madonna, Jay Leno, Margaret Thatcher and many others say the same thing. It seems to be more prevalent in highly ambitious, driven individuals.
I saw a documentary on sleep years ago that followed an even more amazing case of a father and daughter who only needed 1-2 hours of sleep a night. They both held 2 jobs and experienced no negative symptoms. I tried to find this documentary for our weekly brain video, but couldn’t locate it online.
Other genetic variants can play a role in sleep as well. Michel Jouvet, famous neuroscientist and sleep researcher, once studied a 27 year old man with Morvan’s fibrillary chorea, a genetic disorder that kept him from sleeping. He went months without sleep, yet did not suffer any negative consequences associated with sleep depravation. However, instead of sleep, his nights were full of dream-like hallucinations. Perhaps he did not reach a state of sleep as we know it, but his body found a way to compensate somehow, and work around his genetic differences.
Also interesting is how we perceive the amount of sleep we’ve gotten. A study by Dr. Allison Harvey, of Berkley, measured how much sleep a group of insomniacs actually got compared to their perception of it. It turns out that they only received 35 minute less than those who had no trouble sleeping, yet when asked how long they had slept, the insomniacs reported only 2-3 hours of actual sleep. Amazingly, when they were told that they had gotten a good night of sleep, many of the symptoms of sleep depravation disappeared!
So, in many ways, our perception of how rested we are affects how we feel during the day.
Many users of Brainwave entrainment also report a reduction in sleep needs, particularly in the first few months of use. Deep relaxation sessions like those targeting Theta waves, are said by many to replace up to 4 hours of sleep. In a way, this makes sense since Theta is close to the mental state of sleep, and when Theta acts as a kind of “cat nap”, it could naturally reduce your need for sleep. However, what is more interesting is that even people who never use Theta sessions often report the same effect! We even have users of Beta sessions (basically the opposite of sleep) reporting that they need less sleep yet feel more energetic during the day. Though this effect is often temporary, it still raises many intriguing questions.
Not surprisingly, drug companies are working fervently to come up with a way to reduce sleep needs, beyond the jittery effects of Red Bull and coffee. The drug Modafinil seems to help the brain mimic the effects of the “Clock Gene” variant, allowing users to only sleep 4-5 hours a night and still feel as refreshed as ever. A new drug being tested called CX717 promises to allow someone to remain awake for 36 hours or more without the negative effects of caffeine.
I do wonder if there are any long term problems with sleeping less, even if we are genetically gifted to do so. I read one study that indicated it could be a problem for women more so than men. It seems to me that if there wasn’t a major biological disadvantage to sleeping only a few hours a night, everyone would be doing it by now.
Still, I can’t help but envy those lucky few who can survive on 4 hours of sleep. I am decidedly average, needing almost exactly 8 hours to feel normal, barring any cat naps or theta sessions I’ve used. Any more than 8, and I feel dazed – any less, and I feel sleepy. Who knows what wonders people could produce with an extra 4 hours of time each day!
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