If you live to 80 years of age you will spend 27 years asleep. That’s a third of your life in the land of nod. It’s a staggering amount of time and what’s even more amazing is that we lack a complete understanding of why we do it at all. A common assumption is that sleep serves as rest. A chance for the body to recharge after a long day, ready to go again the next day. It’s a problematic explanation though as we know remaining still for 8 hours does not have the same refreshing qualities. Perhaps instead sleep is needed for the resting of the mind, but again this is questionable as scans show brain activity can be very high during periods of sleep.
There are however leading theories on this question, with scientists proposing sleep to be a mixture of memory consolidation, general maintenance and an evolutionary hangover from our ancestors. During an eight hour sleep our brains go through a four phase cycle, but only two of these phases serve any benefit to us. The first is the REM (Rapid Eye Movement) phase and it is here that memory consolidation is performed, with a by-product of dreams occurring as the various information from the day flows over our minds like cars sweeping across a city. It’s also a phase that can produce a strange phenomenon as dreams are treated as unnecessary information and therefore are ‘deleted’ from your memory, waking up during a dream though can mean we are conscious during this deletion process and we literally experience the memory disappearing as we struggle to recall it.
The second important phase is called slow-wave (due to observations of our brain activity during this time) and it’s believed this is significant for maintenance and repair work to be carried out in the brain, a chance for connections to be reinforced and general checks to be performed. How then do we explain the other two phases of sleep? Well they appear to be nothing other than ‘ramps’ feeding us down into the important phases and their length is very much linked to our evolutionary past.
WHEN IT COMES TO SLEEP WE’RE VERY MUCH STILL IN THE GRASP OF AN ANTIQUATED ROUTINE
The idea is that our brains use these ramp phases as a way to extend the sleep cycle in order to satisfy various external factors. Evolutionary biologists believe that this was essential for the survival of our ancestors as a longer sleep cycle enforced an extended period of rest, essential for preserving energy, and also hid the individual away at times of darkness where threats from predators could be greater. For that period of human evolution it made a lot of sense, use your energy to hunt for food during the day and preserve it at night when you need to seek safety from predators. Eight hours fits nicely into this and it took our ancestors through the night to the following morning when the sun returned to the sky.
Of course these concerns don’t apply to us today as we no longer have to worry about hunting for food during the day and the threat of predators at night but still we are left with this evolutionary hangover of an 8 hour sleep cycle. The instinct is still there and as soon as the sun sets our bodies start to produce chemicals that make us drowsy and inevitably lead to us seeking out our beds. When it comes to sleep we’re very much in the grasp of an antiquated routine so is there any hope for us to modernise our sleep behaviour?
Well this is where new technology is beginning to step in with techniques such as transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS) both offering a way to shorten the redundant ‘ramp’ phases of sleep by applying small currents to the brain via a headset. These currents manipulate the behaviour of the brain by forcing the next phase of sleep to occur, effectively skipping over the ramp phases and initiating the important part of the cycle much quicker than would normally occur. Early results have shown that it’s already possible to reduce a healthy night’s sleep from 8 hours to 6 hours, a significant achievement.
IT STANDS TO BECOME ONE OF THE MOST TRANSFORMING TECHNOLOGIES HUMANITY HAS EVER CREATED
Of course it’s early days for this technology but it’s not too difficult to imagine a near future where thin headbands allow us to sleep healthfully for 4 hours rather than 8 and by halving our sleep like this we stand to extend our waking lives by 13 years. There are many questions to ask though, like how will we spend this extra time? Will society see a big increase in leisure time and an explosion of creativity from people who finally have the time to finish that book they’ve been writing or will the never ending rat race step up to fill the gap with working hours increasing? Whatever happens it stands to become one of the most transforming technologies humanity has ever created and will be fascinating to experience. Looking even further forward, how would you feel if one day it was possible to negate sleep altogether? A huge stretch of wakefulness stretching beyond from the day of your birth. What implications could that have on how you see the world and your mental state on the whole? The future holds many interesting days to come.