Why Do Humans Have to Pretend to Sleep to Fall Asleep? transcript

Every night we all do something super weird that hardly anyone notices. We have to pretend to be asleep. You lie down in bed, pull up the covers, close your eyes. You try to stay totally still as if you are already fast asleep. But the funny part is you are still awake. Your body is playing the part of someone deeply asleep. While inside your head your brain is replaying a conversation from 5 years ago, worrying about your to-do list for tomorrow, or randomly digging up an embarrassing moment you have tried to forget for a decade.

And then the weirdest thing happens. The act actually works. You just keep pretending and boom, somehow you really fall asleep. Why does a crucial biological process like sleep work in such a clunky way? Why cannot we just lie down and fall asleep in a snap? It turns out this silly nightly habit hides a crazy biological mechanism about how the human brain works. Welcome back to Apex. Today let us figure this out. Why do humans have to pretend to sleep to fall asleep?

And the answer might come completely change the way you go to bed tonight. To understand this weird mechanism, first we need to bust a super common myth about sleep. We usually think sleep is like a light switch. You hit off, the power cuts out, it goes pitch black, your brain stops working, and you fall asleep. Or when you wake up in the morning, someone hits on, the light shines bright, and you are instantly awake.

But sleep doesn't work like that. Your brain doesn't have an instant on/off button at all. Instead, in neuroscience the human sleep and wake mechanism is called the flip-flop model. Imagine there is an intense tug-of-war happening inside your brain between two different teams of brain cells. On one end of the rope, the wake team, wake promoting system, is packed in the midbrain and brainstem. This team's job is to constantly pump out neurotransmitters to keep you awake, focused, and alert to your surroundings.

And on the other end of the rope, the sleep team, sleep promoting system, is located in a special brain area called the VLPO. Completely the opposite, the goal of this team is to send out inhibitory signals, forcing other areas in the brain to cool down and rest. These two systems can't win at the same time. They constantly block each other. When the wake team is stronger, it forces the sleep team to be quiet. On the flip side, when the sleep team builds up enough energy, it overpowers the wake team and takes control.

And here is the key point. The state where you lie down and pretend to sleep every night is exactly when the gray area shows up. That is when these two systems are in a 50/50 tug-of-war. The wake team refuses to let go, while the sleep team is trying hard to pull the rope to its side. You aren't really asleep yet, but you aren't fully awake anymore, either. Without this tug-of-war, if the brain switched from awake to asleep too fast in just a few seconds, that would actually be a sign that something is wrong.

In medicine, that condition is linked to narcolepsy, which can cause a person to suddenly fall asleep right in the middle of the day while working or going about their normal life. So, if you have to go through a period of tossing and turning and pretending to sleep every night, don't be quick to get mad or worry that you are sick. Actually, it is a completely normal biological sign that gives the brain time to safely switch from being awake to being asleep.

But, the question is, how does the sleep team win that tug-of-war? The first factor is a chemical called adenosine. Imagine your brain is a rubber balloon, and adenosine is the water being pumped right into it. The longer you stay awake and think, the more water flows in. This makes the balloon stretch out and get super heavy. This tight feeling creates what science calls sleep pressure. By the end of the day, this water balloon weighs heavily on your nervous system, making you want to close your eyes.

However, there is a fun fact. The chemical pressure from adenosine alone is not enough for the sleep team to win. It needs extra signals from your actions and the environment around you. Why is that? Let us go back in time millions of years ago when our ancestors lived in natural caves or out on dangerous savannas. Just think about it. What if human sleep was designed so that whenever enough adenosine built up, your body just powered off right away, no matter what, even if you were standing in front of a tiger or in the middle of a huge storm, what would happen?

The human race would definitely have been wiped out a long time ago. Because of this, evolution installed a super strict safety check system in your brain. Before the sleep team is allowed to tell your senses to shut down, the brain needs a bunch of proof that there are no threats left around you. And your act of pretending every night is exactly how you actively give your brain that proof of safety. Lying back in bed signals that your body no longer needs to stay balanced to run away or fight.

Closing your eyes instantly cuts off visual information, confirming that your surroundings are safe. Relaxing your muscles proves there are no threats forcing you to defend yourself. And choosing to breathe slowly sends a signal to your nervous system that you are resting, not panicking or running away. Simply put, when you lie down and pretend to sleep, you are sending a message to your brain's security system. Everything is fine.

There are no enemies. There is no danger. The system can safely disconnect now. But how exactly is that message sent? How can you control a whole complex nervous system just by closing your eyes and lying still? The answer lies in a super smart strategy. You are using your own body to hack right into the deepest nerve network of your brain. First up is the reticular activating system or RAS for short. This is a network of brain cells in the brain stem that acts like an information checkpoint.

Every second, millions of signals about sound, light, temperature, and touch flood into your body. The RAS filters this information and only sends the important stuff up to your cortex so you can notice it. When you lie down, turn off the lights, and close your eyes, you are starving the RAS. There is no light to process and no movement to track. Without these outside triggers, the RAS starts to slow down its activity.

This puts your whole cortex into standby mode. Next is the connection between your breathing and the autonomic nervous system. Your autonomic nervous system is made up of two opposite branches. Number one, the sympathetic system or fight or flight. This kicks in when you are stressed, making your heartbeat faster and your breathing quick and shallow. Number two, the parasympathetic system or rest and digest. This activates when your body relaxes, slowing down your heart rate, lowering your blood pressure, and helping you recover.

When you are anxious or trying to force yourself to sleep, you usually breathe fast and shallow. This triggers the fight or flight system to send an alarm signal to your brain. But when you pretend to sleep, you often unconsciously copy the breathing of someone who is actually sleeping. Deep, slow, and steady breaths from the belly. This slow breathing creates physical pressure on the vagus nerve. That is the pathway connecting your heart, lungs, and brain.

When the vagus nerve is triggered by slow breathing, it instantly sends out a biological command. Release a chemical called acetylcholine to force your heart rate to slow down and drop your blood pressure. This can be understood as a bottom-up effect. You cannot just simply order your brain, "Go to sleep." But you can actively change your body state, like by lying still and breathing slowly, to indirectly put your brain into a resting state.

So, when we are lying still and breathing slowly, what is actually happening inside our minds? Now, let's talk about an experience that a lot of us have had. You lie in bed for an hour, your eyes are closed, but your mind is still racing. It feels like time is passing very slowly. And when you suddenly open your eyes to look at the clock, you can only sigh, "Another rough night. I have been lying here this whole time and could not sleep at all." But, the interesting thing is the feeling that you were awake that whole time does not always accurately reflect what just happened in your brain.

In sleep science, this is usually called sleep state misperception. Researchers can use an EEG and sleep tests to pinpoint exactly when the brain and body switch to sleep mode, and then compare it to how the person actually felt about whether they slept or not. And sometimes these two things do not match up. A person might still feel like they are awake, but the tests show they have actually entered a light sleep stage.

Simply put, you think you are awake, but your brain has actually started to doze off. And it is exactly during this time that you might run into a state called hypnagogia, the state right before sleep. This is the middle ground when you are drifting from awake to asleep. During this stage, you will have experiences like hearing vague sounds or someone calling your name, seeing random images and patterns floating in front of your eyes.

Your thoughts become super illogical and make zero sense. Plus, there is another thing that a lot of people have definitely experienced. A hypnic jerk, that feeling of suddenly falling. You are lying still and suddenly you feel like you just missed a step from up high or took a fall making your whole body jerk. Why does this happen? From the view of evolutionary psychology, many scientists believe this is a leftover trait from our ancestors.

When you relax your muscles too fast while pretending to sleep, the part of your brain that hasn't caught up yet might mistakenly think your body is falling out of a tree. It instantly shoots out a rush of adrenaline to make your muscles tense up to grab onto the branch. So, the next time you lie in bed and feel like you keep tossing and turning without getting any sleep, rest assured it might just be a trick and your brain has actually started the sleep process already.

But, hold on, things do not just happen out of nowhere. How does the brain know exactly when it needs you to start pretending? That is when your biological clock steps in. Deep inside your brain, there is a tiny area called the suprachiasmatic nucleus, or SCN for short. The SCN constantly takes in light information from your eyes to help your body sync up with the day and night cycle. When night falls, the SCN sends a signal to your pineal gland to start making melatonin.

That is the hormone that makes you feel sleepy. It does not put you to sleep directly. Instead, it acts like a guide, letting your whole body know night is here, get ready to switch into rest mode. But, the way we sleep today was not always like this. So, how has our sleep changed over millions of years of evolution? To find the answer, we have to go way back in time. If we compare humans to other primates like chimps or orangutans, our sleep has a super unique evolutionary history.

Our primate ancestors used to sleep up in the trees. Up there, they slept to stay safe from dangers on the ground. But, that also came with risks like falling out of the tree or dealing with predators. But, when ancient humans learned to control fire and slowly moved down to live on the ground, everything started to change. The fire brought safety and warmth. Humans started getting solid, longer stretches of sleep at night.

Still, the ground was full of hidden dangers. Falling into a deep sleep out in nature, even with a fire to protect them, meant they had to stay on high alert. That is why the pretend to sleep safety check became so strict for humans. There is a very famous historical theory that says, in parts of Western society before the Industrial Age, people usually had segmented sleep. First sleep, going to bed in the early evening.

The awake time, waking up for a bit in the middle of the night. Second sleep, going back to sleep until morning. And that brings up a really cool point. Waking up in the middle of the night is actually a totally natural part of human history. Our sleep might be way more complicated than just one solid block of sleep from night until morning. Understanding evolutionary history helps us understand our bodies better. But there are nights when the harder you try to sleep, the more wide awake you are.

Why does this backward thing happen? The number one enemy ruining it is cortisol, the stress hormone. When you fall into a state of tossing and turning and start worrying, "Oh, no, it is already 2:00 a.m. I only have 4 hours left until I have to wake up for work." Your brain cannot tell the difference between worrying about work and worrying because there is a wild animal outside. It sees that anxiety as a danger signal and releases cortisol along with adrenaline.

Instantly, your heart rate goes up and the wake team in the flip-flop model takes back the upper hand. At this point, no matter how hard you try to pretend to lie still, your body inside is still in fight mode. So, how do you get through these sleepless nights? Psychologist and neuroscientists suggest two super effective techniques. One, paradoxical intention. Sleep is an automatic system. It is just like digesting food or healing a wound.

You cannot force it directly with your willpower. The harder you try to sleep, the more you fail. The paradoxical intention technique tells you to do the exact opposite. Just lie there, close your eyes, and tell yourself, "I am just going to lie here and rest and try to keep my mind awake for a little bit longer. When you take away the pressure that you must sleep, the anxiety goes away. Cortisol drops and without even trying, the sleep team gets a chance to put you to sleep.

Two, cognitive shuffling. When we lie there pretending to sleep, our brains often have a habit of running logical thoughts, analyzing the past, planning for the future, or calculating money. These logical thoughts are a sign that the pre- frontal cortex is still working hard. The cognitive shuffling technique helps you break this chain of logical thinking by forcing your brain to process random images that have nothing to do with each other.

The way to do it is really simple. You think of a word, for example, the word bed. For the letter B, imagine a bear, a book, a baby. For the letter E, imagine an egg, an eye, an elephant. For the letter D, imagine a door, a desk, a dress. Constantly picturing these random and meaningless images will perfectly copy the free-thinking state, hypnagogia, of the brain right before you fall asleep. It sends a signal to your cortex that logical thinking has let go.

It is time to go into a deep sleep. So, we have gone on a whole journey together to figure out what seems like the silliest human habit every night. It turns out having to lie down, close your eyes, pull up the blankets, and pretend to lie still is not crazy at all. It is a safety feature that evolution gave to humans. It is the time when you patiently send out safety signals, calm your nervous system, and create the perfect setup for your brain to hand over power from the wake team to the sleep team.

Next time you get into bed, pull up the covers, and find yourself pretending to sleep in the dark, do not worry or push yourself to fall asleep right away. Just relax. Your body is simply doing a survival trick that helped our ancestors stay alive for millions of years. You just need to do your part well. Give those safety signals, relax your breathing, let go of logical thoughts, and let the amazing nervous system inside you handle the rest.

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