It helps to know just a little bit about the science and stages of sleep, what researchers call “sleep architecture.” But don’t worry, the science here is pretty simple and intuitive. This will help us target our efforts, and use the induction methods that I’ll discuss in our future sessions at the most optimal time. Don’t waste your time trying to have lucid dreams when you’re in sleep stages that aren’t associated with dreaming. Apply your efforts when you get the biggest bang for you buck, during “primetime dreamtime,” which is the later phases of the night. Understanding these stages will also help you discover why lucid dreaming, when done right, does not interfere with your rest. We leave the “Do Not Disturb” sign up in the early phases of the night, and ramp up our efforts closer to dawn.

The first thing is to understand the two major types of sleep, REM versus non-REM sleep. REM sleep is called paradoxical sleep. Non-REM sleep is called quiet sleep. REM sleep or rapid eye movement sleep is called paradoxical sleep because while the brain becomes more active during the stage, the muscles become more relaxed.

In fact, they’re paralyzed. It’s what’s called sleep atonia where your body basically turns into a kind of ragdoll. It’s nature’s way to prevent you from acting out your dreams. Sometimes when we experience this sleep atonia, that’s called sleep paralysis. If you don’t understand what’s happening, it can be a little bit freaky.

Sometimes I experience it when I’m taking my naps. I wake up, I’m partly awake, partly asleep. It feels like somebody pressing down on me like I can’t move. But if you do understand it, it’s actually a really fascinating stage.

Non-REM sleep is associated with restoration, deep relaxation, and an idling brain. It’s really kind of when your brain downshifts into neutral.

REM sleep is our focus in lucid dreaming and dream yoga. REM sleep itself accounts for about 25% of our sleep. It is indeed associated with rapid eye movement. That’s where the acronym comes from, muscle twitches, the sleep paralysis, I was referring to, and active brain and dreaming. In other words, we’re mostly dreaming when we’re in REM sleep, so this is what we want to target.

In lucid dreaming and dream yoga, we really don’t mess around with non-REM sleep because we’re generally not dreaming that much during non-REM sleep. We don’t want to disturb that restorative stage. The best time for lucid dreaming really is during REM. That’s prime time dream time. That’s when the dreams are really clicking.

Understanding the following stages can really help us determine when to apply our lucid dream induction methods.

We go through five stages when we sleep. Each stage is associated with a particular brainwave frequency as measured by EEG, which is correlated with brain activity. We tend to view sleep as simply a matter of turning off but sleep is actually a very active stage. Our brain activity is more varied during the night than it is during the day, which is surprising to many people.

Here’s a little bit of science, not a bunch, but just a bit. There are four principal brainwave states, beta, alpha, theta, and delta as measured by an EEG or electroencephalogram. Waking consciousness is associated with beta and alpha, and sleep with theta and delta. Specifically, beta waves are in the 30 to 40 cycles per second or what are called hertz and associated with states of concentration and stress. Alpha waves are 18 to 13 hertz and associated with a more relaxed waking state.

When we go to sleep, the brain downshifts from waking beta and alpha down to theta, which is four to eight hertz or cycles per second, and eventually into neutral or the deep sleep stage of delta, which is zero to four hertz.

As brainwaves settle from beta into alpha, we enter this pre-sleep stage called the hypnagogic phase. This is sometimes more recently referred to as kind of liminal phase or associated with what’s called liminal dreaming. Liminal means threshold. So, this is that kind of gap or in Tibetan Buddhist language kind of Bardo state between waking and sleeping.

Hypnagogic comes from the root Hypnos, which is the god of sleep in Greek mythology, and Agogia, which means leading to which is a lovely image for me. Leading towards sleep, leading towards the god of sleep. During this stage, it’s common to have feelings of falling, hearing someone call your name, experiences called hypnagogic hallucinations.

The boundaries between inside and outside self and other get pretty fuzzy and eventually blur out. Hypnagogic phenomena are really particularly interesting for meditators, especially during those long meditation sessions as you dip in and out of sleep on the meditation cushion and therefore in and out of these hypnotic states. Another really common event during this period is called the myoclonic or hypnic jerk. We’ve all had this when you have this kind of sudden jerking motion where you jerk yourself awake for no obvious reason.

Stage one lasts about 5 to 10 minutes and is generally very light sleep. This is when it’s relatively easy to wake someone up. The difference between deep relaxation and slipping into stage one occurs gradually and subtly. If you wake someone up during this stage, they often report that they weren’t really asleep. Brainwaves during this stage decrease from alpha to theta. So, you’re starting to downshift and slow down. We spend about 4 to 5% of total sleep time here.

Stage two, slightly deeper and characterized by a decrease in breathing, heart rate, and body temperature. During this stage, the brain is still mostly in theta but interspersed with two wave features that are, in fact, the defining characteristics of stage two sleep. It gets a little technical here, but these are called sleep spindles. Just a sudden increase in the wave frequency and K-complexes, which are a sudden increase in wave amplitude. This stage lasts generally around 20 minutes. But as with any stage, the time is never fixed. We spend about 45% to 55% of our sleep time here. And so, once again stages one and two are considered light stages of sleep.

Stage three is the beginning of deep sleep when brainwaves drop into that slower delta range. Sometimes stages three and four are actually joined together so this can be a little confusing. Sometimes these stages are talked apart in five stages. That’s the way I’m doing it. But sometimes you’ll see people talking about it, scientists, researchers talking about it in four stages. That’s usually because stages three and four are put together.

This is the beginning of deep sleep when the brainwaves drop into these slower delta ranges. It’s a transitional stage between light sleep and the deep sleep of stage four. There is no clear, crisp distinction between stages three and four, except that stage three is when less than 50% of brainwaves are in delta and stage four is when more than 50% of waves, in fact, are in delta. We spend about 6% of the sleep at stage three.

Stage four, our deepest sleep, lasts about 30 minutes at least in the first phase of the night. This is generally characterized by profound muscle relaxation and deep rhythmic breathing. This is one we’re fully offline. Stage four is restorative sleep, the “Do Not Disturb” sleep, when the body releases things like human growth hormone, undergoes cellular and biological repair, and we get the rest that we need. We spend about 12% to 15% of sleep at stage four. Stages three and four are when it’s the most difficult to wake somebody up. And if someone does wake up from this stage, they’re usually groggy and grumpy, disoriented. Other things like sleepwalking and bedwetting tend to occur at the end of stage four.

Stage five is when things get really interesting for us. This is when we come back up. Instead of coming back up to stage one, we come back and enter a new stage realm. After resting in deep dreamless sleep for about 30 minutes, we briefly come back up to stage two. But like I mentioned, instead of coming all the way back up to stage one, we enter a new stage, REM sleep.

In other words, stage one is replaced with REM sleep. And then after this initial entry into REM, you cycle back down through these stages again. This is when we dream the most. Brainwaves come back up from delta to alpha, which means your brain returns to daytime frequencies. Heart rate and respiration increase and, like I mentioned earlier, voluntary muscles are paralyzed in REM sleep, sleep atonia. There is actually more oxygen consumed during REM sleep than when we’re awake unless you’re doing stuff aerobic in the waking state.

People often worry that lucid dreaming and dream yoga can make them less rested. But since most of our restorative asleep occurs in deep delta wave sleep and dreams mostly occur during REM sleep when the brain really isn’t resting anyway, this worry is largely unfounded. As I alluded to earlier, we go through these five stages four to five times each night in about 90 minutes cycle, so it depends on how long you sleep.

After each REM period, there are brief moments of waking up, usually up to 15 times a night. This is when we toss and turn. This creates an opportunity to bring awareness to our dreams before cycling back down into stage two sleep again.

The first half of the night is mostly non-REM. And unless you’re doing really advanced practices like sleep yoga, you don’t really mess with this first part of the night. You wanna get the deep restorative sleep. But as we transition into the second half of the night, we transition mostly into REM. The very first REM period in the first general 90-minute cycle, of course, is short, about 5 to 10 minutes.

This is why we rarely remember dreams from the early part of the night. We’re not in the dreaming state that much then. If we do tend to have a non-REM dream, it tends to be less emotional, less intense, and often just a recollection of events from the day.

So, here’s the final and important point for us. The best time for lucid dreaming is just before you wake up. As the night progresses, REM periods increase and non-REM periods decrease. So, just before awakening, we can be in REM sleep for 45 minutes to an hour. This is why we mostly remember our morning dreams.

This is primetime dream time. This is all we really need to know. By understanding these cycles, we can tune into the times for ramping up our efforts. Don’t waste your time and energy trying to have lucid dreams in the early part of the night. Get your rest. Wait till REM sleep is at its peak.

Now you know where to target the methods that we’re going to be discussing. And there’ll be some very specific techniques like the wake and back to bed method that directly go after this primetime dream time.

Andrew’s books on lucid dreaming and dream yoga:
Dream Yoga: Illuminating Your Life Through Lucid Dreaming and the Tibetan Yogas of Sleep
Dreams of Light: The Profound Daytime Practice of Lucid Dreaming
The Lucid Dreaming Workbook: A Step-By-Step Guide to Mastering Your Dream Life