Is sleep that important?

When you're tired, your world gets smaller.

Tired pug wrapped in a blanket, struggling to sleep.

We are embodied creatures, which means that the only we have a world or understand anything at all is through our physical bodies. This also means that each of us lives in a different world. That may sound strange, but consider this:

A short person and a tall person board the same plane. For the short person, there’s ample leg room—the space feels comfortable. For the tall person, knees pressed against the seat in front, the very same space feels cramped. Same plane. Different world.

A tall person with no legroom and a short person with ample legroom are seated in an aeroplane.

We might think we live in one shared, objective reality. But in truth, we go about our lives, in our world in profoundly personal ways. Our body—its size, its state, its limits—is the medium through which we engage everything. Without a body, there’s no world for us to experience. No body, no world.

Philosophers such as Merleau-Ponty and Heidegger addressed this. They challenged the idea that we are simply "minds" or "consciousness" which are separate and floating around in the containers of our bodies. Instead, they saw the body not as something we have, but something we are. Our understanding of anything is grounded in our bodily engagement with it. The body is not something we have, but something we are. We think, feel, perceive, relate, and make meaning through our bodies.

So - what does this have to do with sleep?

Sleep is not just a luxury, but it is critical to our perception and our ability to go about the world. As our experiences - experiences of thought, emotion, interaction, relationships, (anything really) - are dependent on our body, there is an argument for taking care of our body. To sleep is to sharpen your ability go about the world in a meaningful way.

If sleep impacts the way your body functions, it impacts your world and your entire lived experience. There's plenty of research to back it up:

Sleep Restriction & Implicit Bias

Chronic sleep restriction impairs your control of your thoughts and increases negative implicit bias. Implicit bias, is a negative attitude towards others who are not part of your group. Your experience of the social world becomes narrowed, and you become less open to the breadth of possible experience and relationships. It increases the likelihood that you jump to conclusions, make split-second decisions about the trustworthiness of others. Said differently:

A sleep-deprived person lives in a world where people who do not look like them feel threatening and unsafe. A rested person lives in a world where people who do not look like them are neutral, or even approachable.

Sleep Dysfunction, Inflammation, and Neuropsychiatric Disease

Chronic sleep disturbances increase the oxidative stress and inflammation in your body. Oxidative stress refers to the increased presence of free radicals in the body, which can cause cell damage, accelerate ageing, and is associated with various diseases. Oxidative stress is also linked with many neuropsychiatric conditions such as chronic fatigue, bipolar disorder, and multiple sclerosis. The good news is that getting sufficient sleep helps lower inflammation and oxidative stress in the body.

Sleep Deprivation's Impact on Attention and Working Memory

Sleep deprivation disrupts your ability to maintain focus, your working memory (where you store current data which is in use), emotional stability, and hippocampal-dependent learning (used for spacial navigation, and recalling past events).

To a tired person, the stack of high-calorie pancakes, sugar, and berries is more enticing than to a rested person.

Sleep Loss & Craving High-Calorie Foods

Sleep deprivation affects the brain regions controlling your appetite and leads to increased cravings for high-calorie foods. This occurs as lack of sleep reduces activity in cortical areas responsible for making decisions about food desirability (how desirable is the croissant?) and amplifying responses in the amygdala.

A sleep deprived person lives in a world where the McDonalds burger or chocolate brownie are much more desirable, and hard to resist. The well-rested person lives in a world where cravings for food are more manageable and have less of a pull.

Sleep Loss, Empathy, & Helpful Behaviour

Sleep loss leads people to stop helping others, whether it be individuals, groups, or society as a whole. When you are tired, the key nodes (areas) in your social cognition brain that light up and say "let's be helpful" become deactivated. When you lose sleep, you are less likely to help the old lady crossing the street, let the busy mom with two kids in front of you in the line, or smile at a passerby. The choices you make to perform acts of kindness daily are significantly reduced. When countries switch to Daylight Saving Time, there is a nationwide 1-hour loss of sleep. The study found that during this transition, the act of donating to charitable organisations is significantly reduced.

The Benefit of Sleep to Emotional Processing

Getting enough sleep helps preserve emotional memories in the long term. Consistently getting enough sleep reduces both physical (automatic) and cognitive (thinking) emotional responses over time. This means that it helps to moderate emotional reactions and facilitate healthy emotional functioning in the long term.

A person who gets enough sleep lives in a world where they are able to process their emotions and develop healthy reactions to them over time, the emotions are experiences as less overwhelming and uncontrollable. A sleep deprived person lives in a world where emotions seems to stay stuck, be out of their control, and on edge.

Like a gardener pruning a stem to protect the plant's energy, your brain prunes unnecessary synapses to enhance efficiency.

Sleep and Synaptic Pruning

Sleep provides a crucial opportunity for synaptic "down-selection." This means that the brain has a chance to recalibrate and remove (trim) all the unnecessary neural connections after learning and having gone about the day. Pruning enhances brain efficiency and prevents neural saturation. In other words, throughout the day you are constantly taking in information - some of which you are aware of, and others which you are not so aware of (such as the feeling of your skin, although this is different for every body). When you sleep, you brain starts to process. It decides what to keep, and what is not so necessary.

Why is sleep important?

Sleep impacts your perception, it changes the very way you experience and go about living. It essentially changes YOUR world. Lack of sleep reduces your ability to live in line with your values, it reduces your ability to be psychologically flexible.

Good sleep sharpens your perception, balances your emotions, and clears your thinking. It helps you build meaningful relationships, empathise deeply with others, and live according to your core values. Without enough rest, your world shrinks—becoming narrower, more stressful, and less fulfilling.

To neglect your sleep and your body is to change the world you live in.

Caring for your sleep is caring for your ability to go about the world. To get sufficient sleep is to change your ability to go about life, the way you perceive life, and the way you experience the world.

Your experience of the world is not fixed. Get some sleep. Growth is possible.