As simple and ordinary as it may seem at first, sleeping is one of the most mysterious processes that happen in our bodies. Most of you know that you need to rest because sleep deprivation is bad and we’ve all been there, done that during our college and university years. But do we really know what’s happening while we’re out unconscious? What is exactly our brain doing and why, contrary to any evolutionary logic, do we have to lie down unawares of our surroundings, totally helpless, for more than just a few hours? Science gives us a few answers, but leaves with even more questions. Here’s everything you need to know about why we snooze.
It’s natural, but why?
Let’s look at it from the Nature’s point of view. Imagine two animals – the one spends the day searching for food while avoiding predators, and rests at night, remaining watchful; the other does about the same, but at night because totally unconscious, losing track of where it is and what’s around. Who has more chances of surviving? Right, the first animal. Yet evolution created both humans and animals in such a way, that we need to switch off completely for at least a few hours. This means that something as dangerous as sleep has much more benefits that we know of. Science has connected sleeping with various memory improvement processes, stress release, and emotional stability, so we know it’s crucial to our well-being. But do we sleep because all these need to happen, or we simply adjusted to carry them out during sleep because during the day we’re too active?
We’re all synced
The Earth has its periods of light and dark, and just like that all plants, animals, humans, and fungi have their own circadian rhythms that heavily depend on those periods. But even in the darkest caves of Mexico the blind fish that have lived underground for millions of years have these rhythms – never seeing the Sun even once! This means sleep is a vital internal process and, as some scientists suggest, it happens due to the necessity to sync all the processes and small rhythms of all cells in our body because obviously each and every one of them has its very own rhythm. But that’s as far as evolutionary theories will get us…and they’re almost impossible to prove.
Sleep is cleansing
And I’m not talking about it metaphorically – sleep actually cleanses your brain! According to research, brain cells shrink considerably during sleep, allowing cerebrospinal fluid to flow freely, flushing out whatever debris has piled up around those cells throughout the day. Now this is some major cleansing cession performed by good ol’brain every night, ladies and gents! Well, the study was done on mice, but it probably works the same way for us humans, too. Another thing that happens during sleep is that all the info you’ve gathered during the day gets filtered and what you don’t need goes to the trash bin. Otherwise our brains would overload with all the useless info about the colour of Tracy’s blouse and each and every car you’ve seen pass by while waiting for that bus.
Being a night owl is genetic… and not
Some of you probably have spent months or even years trying to become that perky morning person who gets up at 6 am, does yoga, prepares breakfast, gets ready for the day, and still has at least half an hour to enjoy a morning read with a cuppa of coffee before heading out to work…While you, on the other hand, go through a session of snoozed alarms, can barely get up at 8, have your morning cup of joe, and then rush to work like crazy (a shower may or may not happen). Yep, some of you good people out there are night owls and that’s a thing you can’t control – you were born that way! Dr. Sam Jones from the University of Exter decided to look closely at the genes of different people to see if there’s an explanation there, and voila! Having studied around 700,000 humans he found around 300 genes responsible for being a morning or an evening person. That being said, genes play only a certain role in making you what you are – the rest is your environment and habits you develop. In fact, studies show it’s all completely modifiable! You’ll just need some dedication and motivation to pull it off.
Blind people also see dreams
Not many people know this, but blind people also have dreams and in those dreams they can see! Well, not all of them. There’s a link between whether the person was born blind or became blind later in life and the ability to see dreams. Those that were born blind and children that got blind at the age of 4-5 or earlier don’t dream like other people, while those who got blind after the age of 5 or later in life have the ability to actually see and have pictures in their dreams. So how exactly do blind people dream then if they can’t ‘see dreams’? According to studies, they have a variety of other senses engaged in a dreaming experience. They can feel movement and other kinaesthetic things (like falling), they hear sounds and music, and can even experience feelings of touch and smell.
Some people simply need less sleep
And back to genetics again…Do you know those lucky people who seem to have more hours in their day than anyone else? Yep, some people need only around 4 hours of sleep to rest and stay sharp, while all the others need 7-8 hours to reach the same state of freshness. Researchers from the University of California investigated a number of short-sleepers and found a specific genome that might be responsible for that special ability. Nevertheless, other short-sleepers didn’t have that genome, but had another genetic mutation. Ultimately researchers agree that it is a combination of genetics, habits, and environment that allows them to sleep less. They might be more efficient sleepers because you can’t really compare sleeping outside the city with fresh air and less noise and somewhere on a street with a busy road nearby.