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Beyond the Lone Islands

Sunday, 3 October 2010

The Importance Of Sleep


Readers who have been following me for a while know by now that I’m rather fascinated by dreams.

One evening this week, I watched a documentary on TV about sleep, dreams and sleep deprivation.

In the program, they followed a healthy young man who had volunteered for experiments involving sleep deprivation. Sleeping in a lab, with electrodes attached, scientists could follow exactly which stage of sleep he was in during different periods in the night, and decide when he should be disturbed or woken up.

For five nights in a row he was not allowed more than three hours of total sleep per night. After that, a series of tests were carried out. They showed clearly that sleep deprivation seriously affects physical health as well as the ability to concentrate mentally.

Sleep deprivation affects the levels of hormones which in turn affect things like appetite, insulin production, the cardiovascular system and the immune system. Had this young man gone on in the same way for some time longer, he would soon have been in the risk zone for diabetes, stroke and heart problems. He also showed very poor results in memory tests, and in driving tests.


In the driving tests, he was exposed to sudden events like a (mechanical) dog suddenly rushing out in front of the car. He hit it every time, unable to avoid it. In these tests too, the scientists were able to follow his brain activity, and lots of “micro sleeps” were registered. If I remember facts right, the driving test lasted for two or three hours, and during that time, this sleep deprived young man’s brain had actually been ‘asleep’ for a total of about 25 minutes.

Tests such as these prove that driving when not having had enough sleep is as dangerous as driving after taking drugs or alcohol. Lots of unexplained road accidents are likely to have been caused by tired drivers.

The good news is, when the young man was allowed normal sleep again, all of his hormone levels etc were also restored back to normal. This in turn proves that when the cause of tiredness is sleep deprivation, the answer is not to keep going with the help of drugs, but to find a way to get the proper amount of sleep.


Dreams were also mentioned. Scientists now believe that the function of dreams (or at least one of the functions) is to help the brain to store memories. Experiments showed that when people are woken up from their first round of dream sleep, in the late evening, the dreams are often not too difficult to relate directly to things that have happened during the day. Dreams that you dream towards morning are often a lot more complicated to sort out. The scientists interpret this as the brain then being further along in its sorting process, connecting the new memories with old ones.



Ginny said...

Interesting stuff. Some people claim that they don't dreram, but that is not true. We all dream, some just don't remember it. One thing I learned here is about late and early dreams. So THAT is why my morning dreams are always so complex!! People who get more sleep don't have as much weight problems, but to me that's because you can't eat when you're asleep! the more time you spend sleeping, The less time you have for eating!! But I suppose it just can't be that simple.

GB said...

That's a really interesting post, Monica, and continues the theme we have discussed so often.

What it might explain is why I had a heart attack many years ago. For a while immediately beforehand I was down from my usual 5 hours sleep a night (which, for much of my life was my usual requirement) to about 3 or 4 hours which I knew was too little.

DawnTreader said...

Ginny, yes, weight problems were mentioned as well. That too had to do with a disturbance in hormone levels, like insulin production. That can make people lose the natural sense of being hungry vs full so that they eat a lot more than they need. And then of course it easily becomes a vicious circle.

DawnTreader said...

Graham, that sounds plausible to me. For me, even five hours a night sounds extreme. I've always been in need of a lot more than that, or I'd be like a nervous wreck of a zombie in the daytime!

rae said...

Interesting post! What's interesting for me is that I read this post MINUTES after telling a sleep-deprived student that their sudden extreme depression might be from lack of sleep over anything else. There's a reason sleep deprivation is such an effective form of torture...


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