Sleep when your alive, not dead
Sleep has played an intriguing role in history. The Enlightenment philosopher Descartes mused that since we experienced the same objects and sensations in a dream as awake how do we know that they are not the truth and our waking hours merely an illusion. Meanwhile, in pre-industrial Europe it was common for people to take two sleeps during the day — what is called bi modal sleep. And in a practice that sounds quite uncomfortable, ancient Egyptians, instead of using a pillow, slept on headrests made out of stone, pottery, wood or ivory.
My own attitude toward sleep throughout life has also been quite peculiar. I was an unusual high schooler, to say the least. Signing up for a zero period class each and every year of high school meant I had to be up by 5am or 5:15am to get ready and get to school on time. Late nights and cramming for tests that defined the high school years of my peers was not for me. I would be in bed at 9pm or 9:30pm at the latest, which meant 8 full hours of glorious sleep. My parents even thought me quite odd, given my night owl brother and sister.
Needless to say, I was called a nerd and was often the student that would help others in Calculus beleaguered by derivatives, or lead European History study session, equipped with fastidious memory.
Science has now begun to reveal the link between my sleep, and my ability to be the tutor, or, in my current professional life, how lack of sleep prevents me from remembering key details from meetings the day before. Sleep enables brains to be cleaner, and finer-tuned for storing memories.
This essay will attempt to dispel from the modern lexicon the saying “I’ll sleep when I’m dead” with The more apt axiom, “I’ll be dead (sooner) if I don’t sleep.”
Hold on, did she actually say sleep made her brain cleaner?
Yes, you got it right.
I’ll delve into why sleep is important for our health and mental faculty, and then offer helpful tips on how to find good sleep. No expensive mattress needed. As a 27.5 year old, I’ve spent 33% of my years, or about 9 years sleeping. Let’s delve into just why and what is going on during those 9 cumulative years.
Brain Cleaning
Our body cleans metabolite waste and toxins from cells via the lymphatic system, a system of tissues and organs that are part of our circulatory system. The main protagonist of the system is our lymph cells. Our brain has a similar system that acts a “rubbish collector,” called the glymphatic system.
Sleep is when your brain’s glymphatic system cleans out the metabolite waste of neurons. Research on the glymphatic system during sleep is relatively new, but has far reaching implications. In a paper by Science from 2013, researchers found “the restorative function of sleep may be a consequence of the enhanced removal of potentially neurotoxic waste products that accumulate in the awake central nervous system.” For a long time, while we knew that our brain was a voracious consumer of energy (~20% of the energy used by the human body), we weren’t exactly sure how all that waste from breaking down glycogen, it’s form of glucose, was carried away. Moreover, the study, utilizing a mouse model, found that sleep was associated with the removal of peptides, including beta amyloid, the sticky plaque that builds up in Alzheimer’s (AD) patients.
Memory storage
There was a theory going around in deep learning circles last year called the information bottleneck. The hypothesis is simple: the network of neurons in deep learning models rid noisy input data of extraneous details as if by squeezing the information through a bottleneck, retaining only the features most relevant to general concepts.
The implication is that in learning, what a network forgets is as important as what it chooses to remember.
Biological research has found this true for humans, not just potentially machines. Sleep enables us to learn by playing a key role in memory consolidation. Specifically, sleep solidifies memories through allowing the brain time to selectively eliminate or maintain newly formed neural connections through dendritic pruning. Dendrites are the receiving end of the neuron and aren’t permanent; they rapidly change, grow, and delete branches, reflecting new, stronger connections to other neurons.
Additionally, memory is organized and consolidated as we sleep. According to a study from 2016 in the Journal of Neuroscience traces of episodic memory acquired during wakefulness and initially stored in the hippocampus are progressively transferred to the cortex as long-term memory during sleep.
Contrary to what those might think, our brain is quite active while we sleep. You can think of this activity as memory replay where corresponding synapses are strengthened for long term storage in the cortex.
Hopefully at this point you are convinced that sleep is not an unnecessary, nuisance and actually a critical part of life. But you also might be freaking out, or maybe not freaking out at all? When I talk to people about sleep, many cite themselves as that person that only needs 5 hours a night. However, they are most likely wrong, they just aren’t self-aware to know it. Our brain is quite good at tricking us into thinking no mental faculty has deteriorated during those late nights powering through an excel model, coding, or partying. But even one hour less of sleep per a night can compromise a person’s thinking and responding abilities, in addition to impacting cardiovascular health, energy balance and immune function. In a scarily titled article in the New Scientist, “ The brains starts to eat itself after chronic sleep deprivation,” researchers found that the glymphatic system that I mentioned earlier goes into overdrive in chronically sleep deprived mice. Specifically pinpointed is excess microglial activity, which has been associated with a range of brain disorders including AD.
So now for the tips on getting better sleep. Sweet dreams are attainable.
1)Get into a routine.
Have you found yourself laying in bed and can’t go to sleep, or just not tired? Set a consistent schedule of when you go to bed and when you wake up so that when your head hits the pillow, the body and brain knows it is time for bed.
2) Turn off the heater.
The body has to cool down when you go to bed, lowering in temperature by 1 or 2 degrees. Set the temperature in your bedroom slightly cooler so that it creates the right environment for better sleep.
3) Don’t use your device(s) in bed.
The bed is for sleep. Not for snapchatting.
4) Minimize caffeine and alcohol.
That late cup of coffee could still be blocking the adenosine hormone that makes you feel tired. While those 3 glasses of wine can block REM sleep, interrupts circadian rhythm, and can aggravate breathing problems.
5) Don’t “make up for sleep” during the weekend.
Breaks tip #1 and still means you are still suffering from chronic sleep deprivation and it’s host of direct and indirect effects on your health and cognitive function.
6) Aim for 7–9 hours of sleep per a night.
We are still learning so much about the brain and the 8 hour mandate doesn’t seem to be the right recommendation for everyone. That’s why the National Sleep Foundation created a range recommendation. Ask yourself how you feel on different amounts of sleep. Are you feeling irritable on 7 hours? Perhaps, 8 is a better target for you. Just as medicine is progressively becoming personalized, personalize your sleep patterns to your own needs.
Happy sleeping!
