What’s All The Fuss With This Sleep Thing, Anyway?
Sleep has been a mystery to many scientist for hundreds, possibly thousands, of years. There have been many theories, from early thoughts of inactivity to newer ideas about brain plasticity. However, there has never been a consensus within the scientific community as to why animals, not just humans, sleep. The only thing that they all can agree on is that all life forms on this earth, in some way or another, sleep.
sleep (Photo credit: Sean MacEntee)
There are many theories as to why we sleep. One of the earliest thoughts was that of evolution and inactivity. This deals with being safe during dark hours. The thought behind this theory is that animal become quiet and motionless when they sleep, keeping them safe from predators. The animals that stayed up at night were more vulnerable to attack then those who slept. This theory, however, falls apart when you think about the fact that you will be able to react quicker in an emergency, or attack, situation, when you are awake and alert than when you are asleep.
A physiological approach to sleep is conservation of energy. When we sleep, our metabolisms slow way down. Because our bodies do not require as much energy when we sleep, we cut down on the amount of resources that we need. This theory is believed by many biologists to be one of the reasons why animals sleep.
Some believe that we sleep to dream. To some, dreaming helps you put events of the day into your memory. It helps
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consolidate everything that you experienced and puts those events into “folders” that will help you recall them easier in the future. However, this area is certainly up for debate. Dreams are another hot topic related to sleep that scientists can not seem to agree on.
One thing that most sleep scientists would agree on is that sleep has more to do with the brain than the body. There has been no evidence to indicate we sleep to recuperate our bodies. All the indications lead toward the brain. But this is where the buck stops and the debate begins. Why does the brain need sleep? This has been the question scientists have been trying to answer for hundreds of years.
A new and very promising new field in sleep research has to do with brain plasticity. This field has to do with the change in brain composition and interaction when we sleep. The studies in this field are helping scientists figure out what goes on with the brain when humans are sleep deprived and what happens with them when we sleep. FMRIs are helping us look inside the brain and compare what the differences are while we are awake, sleep deprived, and asleep. These findings are going to be able to help us learn what parts of the brain are active and inactive while we sleep.
While the reasons why we sleep are, and probably always will be, up for debate, it is one of only a few things that all life forms have in common. And, while I do not know which theory is correct, if any, I do know that sleep is awesome. So, if we never find the real reason for sleeping, I am okay with that, and I am sure a lot of other people are too.
Related articles
- Dreams and Nightmares (socyberty.com)
- Go Back to Sleep [Health] (gawker.com)
- Basic Theories of Sleep (iiteeeestudents.wordpress.com)
- Sleeplessness agitates the brain (sciencenews.org)
- The Power of Sleep (sabinianabalagtasbaliba.com)
- Sleep deprivation has euphoric effects (time4sleep.co.uk)
- Sleep texting on the rise, says expert (time4sleep.co.uk)
There is another theory for sleep that I recall from a previous reading (The Owner’s Manual for the Brain: Everyday Applications from Mind-Brain Research by PierceJ. Howard). If I recall correctly the theory states that sleep is used to clean up the toxins built up during brain activity while we are awake. Certain chemicals are present during sleep (one of which, calpain) is responsible for this brian cleansing. Without sleep the toxins would build to the point where the brain would stop functioning. I like this theory because it has a sound psychological, evolutionary, and psychological foundation.
For more sleep theories see the below links:
http://psychology.about.com/od/statesofconsciousness/p/TheoriesofSleep.htm
http://www.livescience.com/10579-theory-questions-sleep.html
Also, in writing for a general audience try to conserve words. For example you wrote, “These findings are going to be able to help us learn what parts of the brain are active and inactive while we sleep.” This would read easier if it were changed to something like “These findings [may] help us learn what parts of the brain are active and inactive while we sleep.” The acronym fMRI should be spelled out when it is first used in the blog.
It would be interesting to also learn about why some people need 9 hours of sleep, versus others who only need 6. Sleep is so important to our daily lives,but many of us find it so hard to find enough time for it.
Also, it would be interesting to learn how sleeping at different times of the day affects the way one feels afterwards. For example, when I sleep at night, I wake up feeling refreshed. If I fall asleep in the middle of the day, I wake up pissed off and feeling gross.
I think we sleep probably because we would go crazy having to remain awake all the time. And we probably wouldn’t have nearly a long life expectancy if we always remained awake, as we currently do.
Tove, those are great questions. I think I can help answer the second part of your questions. Naps tend to be good refreshers if you know how long to sleep. In the research that I read about sleep, if you take a cat nap (30-45 minutes), this will leave you refreshed. If you take a nap between 1 hour and 3 hours, you might feel groggy when you wake up. This is because you are in the middle of your REM sleep cycle. The first REM cycle starts at about 1 hour after you fall asleep. So, try an experiment and only take short naps during the day; you might find a difference.