There are a few prevailing theories concerning why we need sleep, although it still remains quite a mystery.
One of the most predominant reasons we believe we need sleep is to repair tissues; we know that certain growth hormones are released during sleep, and that long-term sleep deprivation leads to immune dysfunction.
Another reason we require sleep is for the consolidation of long-term memories. Neuroscientists at MIT studied the brains of sleeping rats after performing specified tasks (running through a maze). They targeted which areas of the brain were active during the activity itself, and then matched that map up against areas activated during sleep. What they found was that during the dreaming state the same areas in the rats brains lit up. It is thought that dreaming is a sort of filter, choosing which information to keep and which to throw away.
My favorite, and I think most probable, is a theory concerning energy expenditure. We know that neurons eat up energy like Gordon Ramsey the souls and spirits of innocent children. The brain makes up 1-2% of our total body weight, but uses 20% of our bodies total energy. The idea is that the brain effectively must ‘slow down’ during the lapse in consciousness we so ineffably describe as ‘sleep’; it has to ‘replenish’ its reserves.
Much to my own chagrin and extreme frustration, some people do not need to sleep much at all; and in a few rare cases, none at all. A Vietnamese man (Thai Ngoc) apparently went 33 years without sleep after suffering some mysterious illness; he displayed no symptoms of signs of any form of sleep-deprivation.
Scientists have also mapped a gene (‘Period 3) that could possibly be responsible for how some need far less sleep (four hours) than others. We all know a person like this, the person ‘constantly on the go’; Arie Gold from Entourage or Taylor from the O.C… shut-up, although I hate sleep I dedicate my free-time to dream-worlds.
It has also been well-documented that our perception of how well we rested (how much sleep we had), effects how well-rested we feel during the day (read any study on insomnia if you don’t believe me). There was a documentary (if I find it, I will link it) a while ago about a father and daughter who required only two hours of sleep a night. The father and daughter experienced no negative side-effects, and were both successful members of society, leading happy, fulfilling lives.
Needless to say, pharmaceutical companies are biting at the bit trying to find a chemical derivative that will mimic the results of sleep… or else decrease the need for sleep while keeping the normative consequences of sleep-deprivation at-bay. One drug, modafinil, apparently supplements sleep quite well for some patients; they will sleep 3-4 hours, pop a pill, and then feel as though they slept a full 8 hours… again, without the negative consequences of sleep-deprivation.
I cannot wait for the day when I can actualize my most base desire to stay awake. I hate sleep; always have, always will. It doesn’t help that I have central sleep apnea. But even when I was perfectly healthy I just found sleep to be such a waste of time. I have always viewed sleep as this obstacle I have to overcome in order to enjoy the following day. I’ll go to bed pissed off at my body for needing sleep, and excited because tomorrow morning I know I will feel great.
I don’t know about you, but the day Eli Lilly tells the world we only need to sleep 2 hours a night, is the day I actually look forward to sleep.