You snooze, you lose. It’s a catchy phrase. But sleep is not an optional enterprise. All mammals do it. So do birds, reptiles, and even fruit flies. Rats deprived of sleep apparently die faster than those deprived of food. In spite of these astounding facts, we know precious little about the purpose that sleep serves for us. Why do we sleep?
After sleeping over this question, I went in search of some theories. I came across a few. But first, let’s first get to know the two different types of sleep. “Two different types!” Initially, I was surprised as well.
A little more than a half-century ago, most scientists believed that sleep was an inactive state. Then in 1951, Eugene Aserinsky, a clever graduate student at the University of Chicago, hooked his son Armond to a retooled "brain wave machine" and monitored the boy's sleep deep into the night. Aserinsky observed sharp spikes of activity on his readout, suggesting that Armond's eyes were darting back and forth. This turned out to reflect the distinctive state within sleep dubbed rapid eye movement, or REM. Latter it was hypothesized that this movement was related to dreaming. When we are not dreaming but still sleeping, we are in NREM sleep, or Non REM sleep.
Now that we have familiarized ourselves with the two types, let us try and answer the question. There are three major theories that can answer the question. The first among them is the Repair and Restoration Theory:
According to this theory, (I quote) “sleeping is essential for revitalizing and restoring the physiological processes that keep the body and mind healthy and properly functioning.” This theory suggests that NREM sleep is important for restoring physiological functions, while REM sleep is essential in restoring mental functions.
To understand this in simple terms, let us think of our bodies as a car. I presume everyone here, other than me, owns a car, or do I have company? Now you will all know that no car can keep going and going without a...