Three eras of sleep science and why you should know about it

This is the first article in the series of articles on the subtle science of sleep and how you can use it to make sure your body is getting the right “repair” during the night, not just the right numbers of sleep:

So why would you bother to learn the basic facts about sleep even if you think you don’t have a sleep problem?

Simply, because you might have one and might not know about it.
So, late us take a few minutes here to analyze the nature of sleep, different kinds of sleep and how to recognize if you have a sleep disturbance that might have a deep impact on your health without you knowing about it.

Let’s start with a basic fact – Insomnia is not the only sleeping problem. 

You might be getting 7 or so hours of sleep and still not getting the “right kind” of sleep.

The basic problem with recognizing your problems

  • The main problem with recognizing your sleep problems is the fact that you can’t measure the data needed on your own. Because of this, people tend just to go on with their lives hoping “it will pass”.
  • In the meantime, your covert sleep problems are taking a serious toll on your health.
  • So you have two options: sleep clinic or a personal sleep monitor that will allow you to this in your own bedroom.

The sleep monitor that I am using worked great for me.

You can read more about the sleep monitor I am using here.

Simple fact that changed the science of sleep

For a long time, sleep was a mystery and science knew little or nothing about it. You could say that the history of the sleep science is divided into three eras.

Era I:

Before the 1930s, the scientists deemed sleep as a part of human activity that’s beyond the reach of science.

Era II:

This all changed in the 1930s when scientists discovered one simple fact – that the changes in the brain waves during sleep showed measureable results on the skin of the sleeper – a weak surge of electrical current. Different waves (slow, fast, weak, strong) depend on the where in the brain they originate from and the type of stimuli causing them.

Simply put – the brain waves shown on EEG (sleep monitor) depend on what is going in your brain, what sleep are you in at the moment, are you dreaming or not and whether there is an outside influence (music, light…).

These are the years where the sleep research revolution happened and medicine started seeing sleep for what it really is – a complex and dynamic process that has a deep impact on how our bodies work the rest of the day.

Era III:

In the last decades so many sleep research has emerged that gives us precise insight into our sleeping patterns. This doesn’t solely relate to doctors and scientists but, if simplified enough, can give you, the average Joes sleeper an insight into whether the quality of your sleep is robbing you of your health.

For those without sleep problems, sleep is simple and completely taken for granted. For the rest of us, after a while, it becomes a skill that you learn. This can involve relaxation techniques, choosing the right mattress, choosing the right pillow, music, mellow light…whatever works…

This is not an article about insomnia, so let base the foundation for explaining the finer, more subtle sleep disturbances.

Different kinds of sleep

Scientists divide sleep into two types: quiet sleep (non-REM) and REM (Rapid Eye Movement) sleep also known as dreaming sleep.

Understanding how different these two are can give you insights into simple every days facts that can help you understand why you might be getting enough sleep and still, as many people tell me, “waking up tired and sluggish”.

It’s all sleep, granted, but just to be able to get my message clear enough here I will go a little overboard her and say that the difference between these two basic kinds of sleep is so big that it can be compared to being asleep and being completely awake.

Quiet sleep – and idling brain in a movable body 

In this phase, brain activity and “thinking” slow down that it almost completely shut down but the body still moves. This idle sleep is completely clear in the behavior of the brain waves during this phase.

4 Stages of Alpha sleep

As you close your eyes your brain, in the absence of visual stimuli, slowly flow into a state called “relaxed wakefulness” when you are still awake, but the brain does its thing preparing you for sleep. On the EEG, this state read as about 7 to 10 cycles per second (image 1).

image 1_relaxed_awakefulness

Stage 1: 

The next step of the transition happens as your brain slows down further to 4 to 7 cycles per second. This is called theta waves sleeping and lasts for about 5 minutes (image 2).

It is characterized by: 

  • slow muscle relaxation
  • a drop in body temperature
  • slow side to side movement of the eyes

image 2_stage1_of_alpha_sleep
Some people may describe this phase as being light asleep while others might say that they were just relaxed. In all people, this stage is easily disrupted with any outside stimuli like a sound or light, your partner moving around in bed.

Stage 2: 

This is the first stage of sleep in the conventional meaning of the word.

It lasts for about 15-20 minutes and is characterized by:

  • the body becoming still
  • heart rate slowing down below the levels of being awake
  • irregular brain activity
  • spindles – short bursts of fast brain activity, lasting about half a second

In this stage, you are still readily prepared to be awoken.

For example, whisper something to the person in this stage of sleep, and it will clearly show on the EEG.

In this stage, EEG registers patterns called K-complexes, which is in plain terms you still being prepared to awake at any moment (image 3).


image 3_stage2and3_of_alpha_sleeep
We usually spend about half of the night in this stage.
Stage 3 and 4 – deep sleep or slow wave sleep:

Now, you are full asleep.

These stages known as deep sleep are characterized by:

  • low number of brain centers active
  • the waves on the EEG are long and more distinct
  • you breath slowly
  • pulse is around 20-30% of that of waking state
  • less response to stimuli, making it more difficult to wake you up

I promised I’ll put this all in perspective about how you could have a sleep problem and not know about it. Here it is – most of the time if you feel like you are sleeping enough but are still tired, you are not getting enough of “deep sleep”.

What happens during deep sleep:

  • Your brain slows down, but your body works “like crazy” on rebuilding your tissue, repair the damage caused during the day. This is primarily regulated by the pituitary gland releasing growth hormone to repair your body.
  • Increased rate of blood chemicals that re-establishes any disturbance in the immune system – making your body more prepared for potential infections and other invaders

As you can see, this is the most important part of your sleeping pattern for your physical health.

When I say “most important” here I am using the term loosely, because obviously, quality deep sleep depends on how good your body is inducing you to this stage through the stage 1 and 2. Ideally, we spend about 20% of our night in the stages 3 and 4 of alpha sleep.
REM sleep or “active brain in the paralyzed body”
It’s fair to say that this is the least understood part of the sleeping patterns. if you look at the name in the parenthesis above you will see that it is just the opposite to alpha sleep. Your body is still and your brain is active.

What happens here is that your brain is trying to “relieve” itself from the clutter of information received while awake. I like to say that REM is brain “going to the restroom”. I might be crude here, but I am saying it to get the message about the nature of REM more clearly.

Getting into dreams have a deeper meaning and why do we dream in the first place is beyond the scope of this article, and I will not be talking about that. Simple because, on the basic health level, I don’t think it’s crucial for developing and maintaining healthy sleeping patterns.

To simplify – just as stage 3 and 4 of deep alpha sleep restore your body – REM sleep cleanses and restores your brain to “make room” for new information by getting rid of irrelevant old ones.

REM characteristics:

  • rapid eye movement (hence the name REM)
  • penis and clitoris become erect
  • body temperature rises

Interesting fact:

What causes our fight-or-flight while we are awake is the sympathetic nervous system. During REM, it is twice as active as when we are awake and still our body hardly moves.

REM is crucial for emotional and cognitive health and consolidating memories:

Putting it all together:

Ok, so by now I guess you understand what I meant when I said that you might have a sleeping problem and not know about it. Your sleeping problem might be a bad balance between the described phases.

Make no mistake, this is serious and in the long run can have a serious impact on your health.

But, how do I know if I have these problems? 

Look for these signs that your balance between the different stages of sleep is not right:

  • you are having problems waking up or getting up when you are awake
  • it takes you long to feel fully awake
  • you are sleepy during the day
  • mood changes
  • chronic need for caffeine

If you can mange it you can change it.

The problem with what I said about the symptoms of “bad sleep” is that it’s relative. Relative in terms that it can’t be measured and that the symptoms listed above can also be brought on by other conditions like depression.

But if you are not depressed, you should seriously consider taking a close look at your sleep.

There are two way to do this

  • in a professional clinic
  • or in your own bedroom using sleep monitors.

I personally have a sleep monitor (FitBit Sleeping Tracker), and it worked great proving that I do, in fact, have a sleep problem.

Read the review of FitBit sleeping Tracker here: Fitbit Ultra Wireless Activity Plus Sleep Tracker Review.

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James Menta

Camping Gear Reviewer at
Three things you need to know about James - he holds a degree in Materials Technology from the University of Michigan in Ann Arbor, he is a zealot for the great outdoors and he can never find his glasses.       In brief intermissions between looking for his glasses, he is the Editor-in-chief of

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