Sleep is Fascinating: Imagining Eight Hours of Sleep

?? Sleep is fascinating! ??

??When we sleep, we alternate between two types of sleep that come together in cycles that lasts about 90 minutes each. The picture with this post is essential in noticing this.

??If we sleep the 7 to 9 hours most people need, we should complete about five of these cycles. Notice how each of them, while similar, are a little different each time.

??During the first cycle, the brain spends a lot more time in the deeper phases of non-rapid eye movement (NREM) sleep. This is when a lot of restorative activity occurs, including the drainage of toxic waste that built up during wakefulness and tissue growth/repair. NREM phases of sleep are also when connections/memories deemed less important may be trimmed from the brain while also a sort of 'file transfer' takes place from short term to long term memory of new experiences/information from the previous wakeful day.

??As we sleep through the night, each cycle includes less and less of the NREM sleep and more and more of REM (rapid eye movement) sleep. Marked with literal rapid eye movement and increased brain activity (compared to NREM), REM sleep is a time for consolidating and solidifying memories, as we form creative solutions to problems and novel ideas. This is also when we experience the fascinating phenomenon called dreaming.

??Notice how, as each 90 minute cycle ends, it may appear as the brain comes to wakefulness. It just may be, even if we are not conscious of it. But, aside from disturbances (such as noise) that may wake us during the night, the transition from one sleep cycle to the next are times we have opportunity to wake up, even if just for a moment to adjust body position.

??Imagine cutting sleep short by two hours, such that instead of sleeping eight hours, someone sleeps for six hours. Logically, they are losing 25% of their total sleep time. But, considering the varying sleep cycles, it is evident that by losing those two hours, they are losing out on proportionally more REM sleep than NREM sleep since that type is prioritized in (making it a greater proportion of) the later hours of the approximately eight hour sleep opportunity.

??Imagine another scenario common of modern day of using an alarm to wake up and having that wake up time unfortunately occur in the middle of a sleep cycle (perhaps while in a deep stage of sleep). This could be a reason for feeling tired and very unrested even if we have slept for a considerable amount of time. When possible, it is much better to allow the brain to wake us up on its own when it has finished a sleep cycle, rather than using an alarm to force us awake.

??Much more can be said about sleep, including common disturbances to sleep and resulting tips for getting better quality and quantity sleep. Yet, this part that I have just described truly fascinates me and is something I believe should be taught in every school for every one of us.

*Sleep graph from the book ‘Why we sleep: Unlocking the power of sleep and dreams’ by Matthew Walker, which inspired this post that I hope may help at least one person.

Walker, M. (2017). Why we sleep: Unlocking the power of sleep and dreams. New York. Scribner