why are we never aware of the exact moment we fall asleep?



why are we never aware of the exact moment we fall asleep?

In: Biology

Because the initial stages of falling asleep requires you to lose consciousness before you are fully asleep. This is why we don’t recall it.


**TL;DR** There’s no *exact* moment when a switch flips and you fall asleep. Instead, your conscious thoughts drift away until only sleeping thoughts are left over. Because some people have clear memories during sleep, a lot of people still think they are ‘awake’ until they enter REM sleep (and some still think they’re awake then). Some people train to keep conscious thinking while asleep, in order to remember or control their dreams.

EDIT: Thank you kind strangers, medals are always a welcome surprise.

Sleep is a very complex process, and neuroscientists have begun to understand parts of it quite well. But there’s still a lot of stories about it which are not researched well yet. Some of this comment will be old science, so if you are interested, definitely learn more from books and interviews by neuroscientists.

The process of falling asleep involves your brain slowly shifting gears into more relaxed operation. A common model is that the brain has ‘stages’ of sleep that look distinct on measuring devices.

Stage 0 would be ‘awake’ and you have a lot of conscious brain activity, observing surroundings and planning action.

As you relax, you enter stage 1, which still feels very awake to people. But during this stage, conscious brain activity shuts off and the brain only turns it back on sometimes (probably so threats and danger don’t catch you by surprise). During stage 1, your thought patterns load and re-experience memories without much conscious control over them.

Then stage 2 begins, and the bursts of ‘awake’ activity stop. Although at this point you have entered ‘sleep’, almost 40% of individuals still have clear enough memory to consider this ‘awake’ and not realize how much their brain activity has been affected. This is the type of sleep some call light sleep. You can be woken up from it more easily than the next stage, because your sense of the outside world is still on, but very slow. The next stage is called Rapid Eye Movement (REM) sleep.

Then two further stages (3 and 4) exist, which include the commonly called “REM sleep”. During these stages, you begin to dream and most of your conscious thoughts have turned off. These are often called deep sleep because you become much harder to wake up and feel groggy if someone does wake you up. These stages almost universally register as “asleep” to the sleeper.

You can train your thought patterns enough to have awareness and a vivid memory during stages 3 and 4 of sleep, in a process called lucid dreaming. Lucid dreaming allows you to (seemingly) wake up during dreams and change them with conscious thoughts. In addition, the training allows you to remember dreams clearly enough to keep a dream journal or interpret them. Lucid dreaming is still very poorly understood, however research is beginning to identify differences in brain activity that suggest how it occurs.

[This article](https://www.livescience.com/19462-fall-asleep.html) gave me some of the context to express the process in more detail.

[This 2019 research](https://pubmed.ncbi.nlm.nih.gov/30880167/) discusses current research about lucid dreaming and comes to a preliminary conclusion about which parts of the brain cause it.

Sorry, but half of the time I literally fall asleep. Means, I put my smartphone away, lay on the side, take a deep breath and I am instantly asleep.
Now some might say that I am not sleeping because it only counts when I my muscles start that little shake or I am in REM Phase. But I can tell you that I am not thinking actively over sth more than 10 seconds and then I am sleeping.
No alcohol or drugs.

In a way, you either are awake enough to agree not to be sleeping, or you’ve lost enough consciense to not even know what’s happening (not know you’re falling asleep).

Waking up, on the other hand, makes you go from a state of unconsciousness to being awake. So as soon as you notice your thoughts, you say you “woke up”.

Because what makes you sleepy is the production of the hormone melatonin, produced by the pineal gland in your brain. The level of melatonin fluctuates with the light your can see, regulating your circadian rhythms to coincide with the day/night cycle.

So, the effects of sleep aren’t like a signal through your nervous system, immediately triggering unconsciousness, they’re a gradual reaction to the rising melatonin levels in your bloodstream, resulting in drowsiness and eventually, unconsciousness.

The short answer is, you’re not conscious of becoming unconscious, because the very circumstances which make you alert prevent sleep.

It’s like shutting down a computer, a lot of processes running in the background start shutting down before shutting the whole system down. You don’t just unplug the computer.

We may be aware of the moment we fall asleep, if the act isn’t recorded into memory.
So, in this scenario, we are aware, but never remember, food for thought.

You stop being concious, gradually. It might be common to think that there’s a ‘you’ that watches your conciousness turn off. That’s just not the way it happens. When you start losing conciousness, you probably wont even notice until the light fads out. Your brain, when you fall asleep, doesnt give a damn about reality. Its an 8 hour shift of cleaning and organizing. Just lay there and don’t move. You can resume whatever narrative you call a life tomorrow.

I actually know the moment I fall into sleep most nights, because I have severe hypnic jerks (bodily twitches that occur literally as one falls asleep). My head will start twitching really hard against the pillow and it’s always the last thing I remember. It used to scare me until I discovered it was a harmless thing; now I kind of enjoy it because, in a very far-off half-conscious sort of way I’m like “yay I’m about to sleep.”

How could we be?

If we were still aware, we wouldn’t be asleep.

Also, while you may not be “aware” of exactly when you fell asleep, you *will* have a last moment you remember being awake.

I remember once reading a theory that the break in consciousness when you fall asleep is tantamount to a death of the self.
When you wake up, you have all your memories but you are a new person.
Kind of like if a teleporter copied you perfectly and destroyed the original.
Is the copy a copy, or is it the same person?


What people haven’t mentioned so far is that you actually have two forms of memory. You have:

* Short-term memory that handles everything you do right now and keeps your train of thought going.
* Long term memory, that remembers things for more than just a few minutes.

Moving things from short term memory to long term memory is called consolidation, and when you’re falling asleep not only are your thought processes moving to a less conscious level (not really shutting down, but becoming less active and doing different things) but this process of storing memory is disrupted (or at least less effective).

So not only will you not remember the exact moment you fall asleep, but you will also have problems remembering a few seconds or even minutes before the moment when you fall asleep. For example, if you were reading you might not remember the last page you were on.

You can be conscious without recording memories. Blackout drunks and toddlers don’t remember what they’re doing later, but they’re still thinking and taking actions.

You may well be aware of falling asleep, and then promptly forgetting to remember it.

I always thought, imagine if falling asleep was insanely painful, but we never remembered and we were paralyzed while it happened. Like every night you had five seconds of paralyzed agony that you immediately forgot and none of us knew it.

I have been trying to find this moment my whole life. I have been lucid dreaming since I have had memories.

Your brain speaks nonsense when you are falling asleep. If you do mindfulness practises you might know what I’m talking about.

Time skips weirdly and you stop being aware of external noises and eventually you are dreaming. Your thoughts stop being thought nonsense and start expressing themselves as dreams.

I became aware of this quite recently. My second born was a little more difficult putting to bed, I would end up rocking her and telling her bed time stories so she could fall asleep, the problem was that I would usually fall asleep before her. But since I was telling the story I could hear myself becoming incoherent and drifting away! It was the weirdest thing, I could tell exactly when “the three little pigs” became “the three little gibberish” and then they would trail off into nothing as I entered La La Land. Totally insane.

I actually often do know when I have fallen asleep. I have sleep problems and for years did not get good sleep leading to me often having lucid dreams where I know I’m dreaming and can basically control my dreams.

Now when I am trying to go to sleep I am usually thinking about various things. Very often I will suddenly realize that what I am thinking about no longer makes any sense and I am now starting to dream because I have fallen asleep.

Buzzkill here. I have narcolepsy. And I experience a very strange phenomenon in which I do not go through the normal stages of falling asleep. I drop directly into REM sleep. Usually within 2 minutes of laying my head on the pillow. It’s actually a really good situation at bedtime.

I *do* know the exact moment I fall asleep because I go so fast between awakeness and REM sleep. This has been documented. Doctors and sleep technicians think I’m pretty cool. But this is extremely rare. It’s really really nice feeling, just like a switch, but I understand if other people in the forum think I’m absolutely nuts.