Three sheep, four sheep, five sheep… and thus you count yourself to sleep.
Human beings have an average slumber time of 8 hours. That means we spend almost a third of our lives sleeping.
But Why? What is so alluring about sleeping that every time the clock hits eleven (granted you regularly sleep around eleven), your eyelids begin to droop automatically and you begin to feel drowsy, even when you wish you’d rather be completing your office assignment or continuing another hour of chat with a far-distant friend on Facebook?
Those of you who’ve seen or read Fight Club know that the protagonist (played by Edward Norton) is an insomniac whose inability to sleep leads to rather dramatic and tragic consequences in his world. Although nothing so surreal ever occurs due to sleep-deprivation in real-life, it has damaging effects nonetheless. From impaired memory and creativity to heart attacks and obesity, stakes are pretty high.
But before I give you nightmares over skipping few hours of snoozing last night (pun intended), you need to know how we actually doze off.
Don’t think that when you hit the hay and pass out for the next few hours your mind remains passive. Nope. To the contrary, sleeping is a very active process and transitions through five stages. One complete cycle of all these stages lasts about 1.5 hours and recurs until you get up. A summarized breakdown of what happens during these stages I’ve presented below:
- First Stage: You jump on to your bed (or not, in case you’re too tired and just flump on it), grab the pillow, and tuck it under your head. As you slowly drift to the sleepyland, your muscle activities slow down (although your legs or arms may twitch occasionally).
- Second Stage: Your body temperature drops, and so do your breathing and heartbeat rate.
- Third Stage: This is where things start to get interesting. You enter the ‘deep sleep’ mode, during which your brain starts emitting something called delta waves (under normal circumstances, your brain exhibits alpha and beta waves and in the first stage of sleep, theta waves). Don’t panic over the technical mumbo-jumbo, you’ll learn its significance below.
- Fourth stage: This is the stage of very deep sleep, also known as non-rapid eye movement (NREM) sleep. It is sort of being like dead. Near the end of this phase, your whole body is paralyzed (I’ll tell you why) by hormones, your breathing becomes rhythmic, and delta waves are now consistently produced. It may interest you to know that in Advaita Hinduism, it is believed that this is the state of highest consciousness (that is, if one’s actually awake and his brain waves are delta). All the meditation practices focus on reaching this particular mental state, a truly relaxed moment. Remember when you’re feel grumpy and tired upon rousing? That happens if you wake up either during third or fourth stage.
- Fifth stage: Now this is probably the most exciting phase, literally. Your brain activities jumps back to their normal mode, as if you were awake, and this is the phase where your eyes are dashing back and forth in their socket like crazy (rapid-eye movement or REM). But more importantly, this is the stage where dreaming occurs (it occurs in NREM mode, too, but its occurrence and recall are significantly lower in proportions). As I mentioned, your body is paralyzed in the previous stage. This happens so that you don’t act out your dreams (imagine what would happen if you’re dreaming of training with Bruce Lee and actually kicked or punched in the non-dreamy world). Those whose bodies are not properly paralyzed do end up re-enacting their dreams and make for a very lethal bedfellows. Sleepwalking is also a consequence of this malfunction. Remember when you wake up feeling refreshed or when you can recall your dreams vividly as if you’ve been awake the whole time? That happens if you wake up during this stage.
All these stages take about 1.5 hours, as mentioned earlier. And it’s ideal to wake up during the 5th stage, as noted above. So next time, set your alarm in a way that you’ll wake up after a multiple of 1.5 hour (like 3, 4.5, 6, 7.5). For example, if you fall asleep at or about 11, set the alarm at half past six.
Alright, that was all about sleep mechanics. Now, we get to the why part – why is sleep so important?
You know how you feel after one sleepless night – puffy-eyed, rubbernecking at everything like a lost cow and feeling the world around you spinning, as if you were suffering from hangover. So that kind of experience can’t be good in long run, can it? Guess what, you’re right.
Ever heard of Three Mile Island? Chernobyl? Two of the biggest nuclear disasters in the history, all because their operators didn’t get enough sleep (okay it wasn’t the only factor leading to both meltdowns, but experts do include it in the top 5 list). Apart from blowing up nuclear reactors, lack of sleep can be dangerous at individual level as well. Although it doesn’t directly hit your physical well-being (unless you happen to be working at a nuclear power station), it can do so in time. For example, little to no shut-eye bumps up the production of hunger hormone gherlin and steps down that of leptin, the hunger-balancing hormone, leading to excessive hankering for food and to a voracious appetite similar to Garfield’s.
But more importantly, it can seriously hamper your mental and creative abilities. While you sleep, a tiny part of your brain called hippocampus consolidates all sorts of information you collect all day long (and by information here I don’t mean the bookish factoids. In this context, it’s an umbrella term for everything you see, hear or learn). Hippocampus reorganizes and archives them in the form of memory. In fact, different stages of sleep play important role in developing different kinds of memories. NREM stage focuses on storing information while REM stage on storing your skills. If you skip sleep, your brain will miss out these important processes. Besides, this kind of truancy also robs you of your alertness and concentration, not to mention impairing your judgment alongside, too.
So the next time you feel tempted to skim off another hour of shut-eye for meandering on Facebook, think twice.
- An article from Psychology World on the stages of sleep
- An article from WebMD on the effects of sleep deprivation
- An article from Futurity on the hormones responsible for paralysis during REM sleep
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