Framework for the good life (sleep)
Disclaimer: This essay uses Matthew Walker's book 'Why We Sleep?' as a foundation to explain the importance of sleep and how it fits into the framework for the good life. Since the publishing of the essay, I have encountered a piece that refutes some parts of what Walker says with proper scientific evidence. This casts a shadow on Walker's credibility and I have edited the post to remove things that might be controversial. The references that remain are verified explanations of how certain processes happen, but reader discretion is advised. I personally believe that although he might have overstated some aspects of it, overall sleep is very important and there are other compelling science-backed arguments in the book/other sources to make one believe so.
My ignorance and the sense of hubris over my lack of sleep during my late teens and early adulthood now seem incredibly foolish. Growing up in a society that glorifies sleeping less and coins phrases like burning the midnight oil to mean hard work misleads us into accepting that sleep is dispensable. Add to that the constant reinforcement of hearing about top CEOs and politicians managing with four to five hours of sleep and it becomes aspirational to sleep less. Like most other people, I had been conveniently believing and enforcing it.
There wasn’t much of a discernible difference that I felt when I was getting less than the recommended seven to nine hours. But it turns out that we are not equipped to evaluate our exact requirements for sleep because although we get by with less but it actually has hugely detrimental consequences on our cognitive health and well-being.
My view changed when I was first introduced to Arianna Huffington’s story.
One day in 2007, Arianna Huffington was at home on the phone and checking emails when she passed out, fell, and woke up in a pool of blood, with a broken cheekbone and a cut over her eye, according to this week’s People magazine.
Huffington, who had been working 18-hour days building the Huffington Post website, was terrified. After weeks of medical tests, doctors finally came back with a simple, if disturbing, answer: She was exhausted.
Now recovered, she told the magazine she tries to get more sleep and is grateful for the “wake-up call that changed my life.”
Post this incident, she went on to build Thrive Global, a company aimed at reducing burnout and stress in the modern day knowledge worker. I listened to her on the Tim Ferriss Show and something about her experience resonated with me.
A meaningful shift in my approach to sleep though happened when I read Why We Sleep by Matthew Walker. The book has been life-changing. It helped me understand the biological, psychological and evolutionary dimensions associated with sleep.
I’ll condense some of what I have learnt in this essay. Specifically touching upon the following:
- The mechanism of how sleep works, its connection with the various critical functions in our lives and how certain optimisations in factors affecting these mechanisms can help us sleep better.
- How sleep helped us evolve and establish dominance over the other species.
- How it fits into our framework for the good life and what does it mean for the core and auxiliary aspects of life.
How do we fall asleep?
Circadian rhythm is our body’s internal 24 hour clock that creates a cycling day-night rhythm in our body. It is regulated by a hormone called melatonin that is secreted by the pineal gland located in our brain.
The light entering our eyes triggers it. The secretion of melatonin increases as dusk approaches and the pineal gland stops its production at dawn when the brain starts perceiving light (even through our closed lids).
The circadian rhythm also regulates our body temperature and there is a considerable drop as we near our bedtime with it reducing to its lowest point after about two hours of sleep.
An interesting thing to know is that people inherently have different circadian rhythms (determined by genetics) and it also changes over our lifetimes. For some people, the peak wakefulness arrives quite early in the day and for others’ it is a little later in the day (late morning/early afternoon). That’s the reason for people being early birds (40% of the population) or night owls (30% of the population). There is a set (rest 30%) that lies in between with a slight disposition towards being the owl type.
The society is structured to predominantly favour those waking up early—which puts the night owls at an unfair disadvantage. They are labelled as lazy but it is not something that they do deliberately. It is the circadian rhythm that is responsible.
…despite being “awake,” their brain remains in a more sleep-like state throughout the early morning. This is especially true of a region called the prefrontal cortex, which sits above the eyes, and can be thought of as the head office of the brain. The prefrontal cortex controls high-level thought and logical reasoning, and helps keep our emotions in check. When a night owl is forced to wake up too early, their prefrontal cortex remains in a disabled, “offline” state. Like a cold engine after an early-morning start, it takes a long time before it warms up to operating temperature, and before that will not function efficiently.
The effect of waking up early on the night owls
The insight from this physiological process is that in order to ensure a smooth transition to sleep you should control the two factors that can affect the circadian rhythm:
- Temperature – sleeping in a cool room or using other techniques to reduce body temperature such as a warm bath or washing of the face.
- Lighting – reducing exposure to blue light as the day carries on through activating the night light feature on phones and laptops, using warm shades in rooms and use of concentrated lighting (such as lamps) instead of ambient lighting.
There is another hormone called adenosine that is responsible for creating sleep pressure. The pressure mounts with the increase in duration for which we have been awake. Adenosine works together with the circadian rhythm to determine our tiredness and need for sleep.
One can interfere with the functioning of adenosine and consequently put off the urge to sleep. A substance that helps in doing so is caffeine. Here is how it works:
Caffeine works by successfully battling with adenosine for the privilege of latching on to adenosine welcome sites — or receptors — in the brain
Levels of circulating caffeine peak approximately thirty minutes after oral administration Caffeine has an average half – life of five to seven hours
What this means is that half of the total amount of caffeine consumed still flows in the blood even after five to seven hours of intake. It is thus advisable to reduce caffeine intake—more so after evening.
Components of sleep
While we sleep, we oscillate between two distinctly opposite states through the night. These are:
As the name suggests, the states are characterised by the movement of the eyeballs and play different important functions. The NREM sleep dominates the early part of the night and REM sleep’s share increases as morning approaches.
Image from Why We Sleep by Matthew Walker
NREM sleep is the deep sleep that we all crave. It is further divided into four stages based on the depth of sleep where stage 4 represents the deepest state. The most important role the NREM sleep plays is in information storage and strengthening of memory. Whatever we perceive or learn in the wake state is processed in the NREM sleep. Our brain then decides to keep the relevant pieces of newly learnt information (by transferring it into a long term storage site) while discarding the not so useful ones.
As we transition to REM sleep, some meaningful changes take place. First, it is here that we witness our dreams and second, our body goes into paralysis for the duration of our dreams. The paralysis is to ensure that we don’t act on our dreams. If you come to think of it, all you can do is marvel at how nature has designed us in such intricately complex ways.
There isn’t much difference between brain activity during wakefulness and REM sleep because there is a lot going on. Here is what happens when we dream:
In fact, there are four main clusters of the brain that spike in activity when someone starts dreaming in REM sleep: (1) the visuospatial regions at the back of the brain, which enable complex visual perception; (2) the motor cortex, which instigates movement; (3) the hippocampus and surrounding regions that we have spoken about before, which support your autobiographical memory; and (4) the deep emotional centers of the brain—the amygdala and the cingulate cortex, a ribbon of tissue that sits above the amygdala and lines the inner surface of your brain
REM sleep can therefore be considered as a state characterized by strong activation in visual, motor, emotional, and autobiographical memory regions of the brain, yet a relative deactivation in regions that control rational thought.
There are instances when we revisit episodes from our lives in the dreams that cause us pain and despair. At other times, the mere act of waking up from a dream feels mentally exhausting. Naturally, I often viewed a sleep session laced with dreams as a bad one. But REM sleep offers immense benefits and learning these has completely modified my perception. I look forward to dreams now.
There are two ways in which REM sleep helps us:
- It is nature’s way of offering therapy
- It fuels creativity
Our dreams might not be a reflection of what we are experiencing in real life in the exact sense but there’s research that shows that there is considerable overlap in the emotional themes during wakefulness and in dreams.
When we slide into REM sleep, the secretion of a hormone related to stress called noradrenaline stops. What this does is that it enables us to process our life events but without the attached emotional sting. It is an introspective experience that gives an autobiographical perspective to life and helps in emotional healing.
When it comes to aiding our mental prowess, REM sleep is responsible for forming connections between disparate pieces of information stored in the brain thus sharpening our creative and problem-solving capabilities.
The evolutionary connection
Yuval Noah Harari, through his work, has inspired me to look at the origin and existence of things from the evolutionary perspective. Most of our modern day constructs have very logical explanations in our evolutionary history.
Walker makes a strong case for sleep and its criticality by emphasising how despite of it not contributing in a direct way to most of the prehistoric man’s basic needs such as gathering food or reproduction, it has still persisted throughout our evolutionary development.
Addressing the question of why we sleep from an evolutionary perspective only compounds the mystery. No matter what vantage point you take, sleep would appear to be the most foolish of biological phenomena. When you are asleep, you cannot gather food. You cannot socialize. You cannot find a mate and reproduce. You cannot nurture or protect your offspring. Worse still, sleep leaves you vulnerable to predation. Sleep is surely one of the most puzzling of all human behaviors. On any one of these grounds—never mind all of them in combination—there ought to have been a strong evolutionary pressure to prevent the emergence of sleep or anything remotely like it. As one sleep scientist has said, “If sleep does not serve an absolutely vital function, then it is the biggest mistake the evolutionary process has ever made.” Yet sleep has persisted. Heroically so. Indeed, every animal species carefully studied to date sleeps. This suggests that sleep evolved with—or very soon after—life itself on our planet. Moreover, the subsequent perseverance of sleep throughout evolution means there must be tremendous benefits that far outweigh all of the obvious hazards and detriments.
Things changed for us when we figured out how to light a fire. It helped our ancestors move from the trees to the ground and significantly reduce the risk of falling while sleeping. This allowed their bodies to slip into a paralysis and have dreams as a part of the REM sleep. The intensity and efficiency of sleep improved causing us to mature emotionally which led to the formation of strong social bonds and our cognitive intelligence improved. These factors played a critical role in establishing the dominance of Homo sapiens over other species.
Fitting it in the framework
Realising sleep’s importance in our endeavour to live the good life is the most important step one can take.
While we can’t bend societal conditions to enable us to get the required seven to nine hours of sleep opportunity every single night for the rest of our lives, we should at least be mindful and try to ensure that the deviations are as minimal as possible. This will mean choosing cores which allow for this balance, ruthless prioritisation and a lot of saying ‘no’. But given the wide-ranging benefits that we can accrue, I don’t think it is a difficult choice.
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