Healthy sleep consists of several stages, and you cycle through these stages four to five times during the nightly sleep cycle. As a result, you’re progressively descending into deep sleep and ascending toward lighter states of sleep several times, and this cycling is tremendously important, both from a biological and psychological perspective.

During stages 1 and 2, your brain remains active as it begins the editing process where decisions are made about which memories to store and which to discard. During stages 3 and 4, you enter into a deeper, almost coma-like state, during which the actual physiological cleansing and detoxification processes in the brain1 take place.

Your brain cells actually shrink by about 60 percent during this deep sleep phase. This creates more space in-between the cells, giving your cerebrospinal fluid more space to flush out the debris. Lastly, in stage 5, you enter rapid eye movement (REM) sleep, where dreaming takes place.


All of these stages are important, and it’s important to cycle through them enough times each night — especially the deeper stages, and the longest and deepest REM cycle typically begins around six hours after falling asleep. If you only sleep five or six hours, you completely miss this important stage, and when deep sleep stages are missed, your brain gets clogged with debris associated with Alzheimer’s disease. You also forgo the psychological benefits of dreaming.

Why Dream?

Even if you accept the idea that sleep is important, you might not consider dreaming to be very high on your list of biological imperatives. Alas, you would be wrong. Dreaming actually serves a number of important functions. (Later I’ll also address the potential benefits of lucid dreaming, i.e., when you become aware that you’re dreaming while dreaming.)

Rubin Naiman, Ph.D., a clinical psychologist and a sleep and dream expert, suggests thinking about the stages of deep sleep and REM sleep as different kinds of nourishment. “Sleep and dreams are a bit like water and food to the psyche, to the soul, to the mind,” he says, and for health, both are necessary. According to Naiman:

“Dreaming is essential. In recent years, there’s been a lot of research underscoring the fact that dreaming has functions very different from sleep. I think of the dream as being a digestive and assimilating process for information …

If we think about all of the information that we’re exposed to in the course of a single day — the conversations, the things we read, the things we see, hear and think about, and the things we just experience all-around through our senses — all that information can be understood as something we consumed.

What happens in REM sleep is all of this information that we’ve metaphorically swallowed is digested and assimilated. It’s sifted through. Again, in its wisdom … the brain decides what it’s going to keep and what it’s going to let go of.

As this information is digested, that process of assimilation shows up metaphorically in the dream, in the images of the dream. The bottom line here is that if you don’t dream well, it has a profoundly negative impact on your memory. In a deeper sense, it’s as if you stopped growing psychologically. You stopped adding to who you are.”

Dreaming Benefits Creativity and Protects Mental Health

Professor Matthew Walker, Ph.D., founder and director of the University of California Berkeley’s Center for Human Sleep Science and author of “Why We Sleep: The New Science of Sleep and Dreams,” takes it a step further, noting that “Dreaming is essentially a time when we all become flagrantly psychotic.”

However, while this may sound disconcerting, it’s actually a good thing, as it both unleashes creativity2 and protects your mental health. When dreaming is suppressed by chronic sleep deprivation, that’s when you run a very real risk of experiencing a psychiatric breakdown.

In a very real sense, when you forgo sleep for extended periods of time, your brain enters the REM cycle while you’re awake. In other words, your brain is dreaming even though you’re awake, resulting in wild hallucinations, delusions, mood swings, and paranoia. While this is perfectly healthy during sleep, it becomes extremely problematic during wakefulness.


Less extreme cases of sleep deprivation typically involve short-temperedness, moodiness, illogical thinking and irrational behavior. The reason for this is because activity in your prefrontal cortex — the “CEO of your brain” that rules rationality and logical thinking — is dampened. If you frequently feel emotionally off-kilter or struggle with a short fuse, chances are you might manage your emotions a whole lot better were you to get more sleep on a nightly basis.

Deep Sleep Aids Problem-Solving and Provides Life Meaning

Research suggests non-REM sleep and REM sleep contribute to creative problem-solving in different albeit complementary ways. During non-REM sleep, your brain replays memories that are thematically related and organizes new information into useful categories or thematic schemas.

Then, during REM sleep, your brain starts to combine these categories, creating novel points of connection between them, however farfetched or unlikely — hence the “impossible” aspects of many dreams. On the other hand, this random linking of information is also how many new inventions are conceived.

As old and new memories are integrated to form a new whole, new possible futures are also imagined. This is what you actually perceive as “the action” of your dream. The sum total of these processes also allows you to extract meaning from life events.

Enter Lucid Dreaming

But what about lucid dreaming? As mentioned, lucid dreaming is when you suddenly become aware that you’re dreaming. It’s like waking up, albeit you’re still in the dreamscape. When this happens, provided you don’t fully awake but stay in the dream, you have the ability to shape and alter your dream at will.

While this may sound like a novel concept, an estimated 20 to 30 percent of the population are natural lucid dreamers, and research5 has found about 77 percent of adults will experience it at least one spontaneous episode of lucid dreaming. Medical News Today reports:

“The very first record of lucid dreaming appears to feature in the treatise ‘On Dreams’ by the ancient Greek philosopher Aristotle. In it, he describes an instance of self-awareness during a dream state.

‘[If] the sleeper perceives that he is asleep, and is conscious of the sleeping state during which the perception comes before his mind, it presents itself still, but something within him speaks to this effect: ‘The image of Koriskos presents itself, but the real Koriskos is not present,’ he wrote …

For some people, it occurs spontaneously. However, others train themselves to start dreaming lucidly, or to become better at it … Other people may be able to influence their own actions within the dream, or parts of the dream itself …

An experienced lucid dreamer might be able to ‘go on an adventure’ and interact with people and things in a way that they may not be able to do in real life.”

Is Lucid Dreaming Real?

In the featured video, Walker discusses lucid dreaming, noting that researchers have been able to objectively confirm — using fMRI scanners — that when someone claims to be doing something in a lucid dream, they are in fact doing it.

In one study, participants were asked to clench their fist, which lit up certain parts of their brain. They were then asked to go to enter a lucid dream state, and clench their fist again, which resulted in the same brain regions being activated.

Other recent research cited by Scientific American discovered that when you are lucid dreaming, your eye movements are near identical to the eye movements you make when you’re actually viewing something. Called “smooth pursuit” or “smooth tracking,” these eye movements do not occur when you’re simply imagining an object or scene. According to the authors:

“Our findings suggest that … the visual imagery that occurs during REM sleep is more similar to perception than imagination. The data also show that the neural circuitry of smooth pursuit can be driven by a visual percept in the absence of retinal stimulation and that specific voluntary shifts in the direction of experienced gaze within REM sleep dreams are accompanied by corresponding rotations of the physical eyes.”

Therapeutic Aspects of Lucid Dreaming

According to Denholm Aspy, a lucid dreaming researcher at the University of Adelaide in Australia,9 lucid dreaming is not only fun, it can be quite therapeutic, especially if you struggle with phobias, recurring nightmares and/or post-traumatic stress disorder.

It can also improve quality of life for those with physical disabilities that prevent mobility, and improve athletic performance or physical rehabilitation after injury through dream rehearsals. On the other hand, it’s best avoided if you have certain mental health problems. Schizophrenia, for example, can be exacerbated by lucid dreaming. Aspy tells Medical News Today:

“If you can help someone who’s having nightmares to become lucid during that nightmare, then that gives them the ability to exert control over themselves or over the nightmare itself. [L]et’s say you’re being attacked by someone in a nightmare.

You could try to talk to the attacker. You could ask them ‘Why are you appearing in my dreams?’ or ‘What do you need to resolve this conflict with me?’ Some people take on superpowers or special abilities, [so] they can fight back against the attacker … [or] escape …

If a person has a particular phobia, then their lucid dream environment … provides an interesting opportunity to do things like exposure therapy, where you gradually expose yourself to the thing you’re afraid of, in an attempt to gradually overcome that fear.”

Lucid Dreaming Techniques

Can you learn lucid dreaming? Yes. Aspy claims more than half of the people he’s taught his lucid dreaming technique to are able to have lucid dreams within one week. Before you even begin your lucid dreaming experiment, it can be very helpful to simply become more aware of your dreams in general, by keeping a detailed dream journal.

Each morning, write down everything you can remember from your dream or dreams. Aside from training your dream recall, dream journaling can also be helpful by showing you any recurrent themes, which later can act as triggers to help you realize that you’re dreaming.


Mindfulness meditation also trains your mind to remain aware, which can transfer into your dream state, allowing you to become aware that you’re dreaming. Following is a quick summary of three lucid dreaming techniques that have been scientifically identified as being the most effective:

1. Reality testing — Perform reality checks during your waking state. Every couple of hours, ask yourself, “Am I dreaming right now?” Over time, this habit will enter your dreams as well, cluing you in to the fact that, yes, you are dreaming. At the same time, perform a physical reality check.

For example, you might try putting your hand through a wall, or look at an object, look away and then look back. When you’re dreaming, items will tend to look blurry and/or look different each time you look back at them.

2. Mnemonic induction — Before bed, repeat to yourself “Tonight, I will notice that I am dreaming.” Consistently repeated over time, your mind will become accustomed to the idea of becoming lucid while dreaming.

3. ‘Waking back to bed’ — This technique, which I do not recommend, involves setting an alarm to wake yourself up after six hours of sleep. After staying awake for 15 to 20 minutes, you then go back to sleep. The idea is that you will then go right in to REM sleep, and if you intend to remain lucid, it will be easier to do so.

The drawback is obvious — you’re disrupting your sleep, which will have health consequences. So, I cannot in good conscience recommend this strategy. It doesn’t seem worth it to disrupt your sleep cycle just for a chance of lucid dreaming. Instead, work on the first two techniques.

Potential Adverse Effects

While Aspy has not found lucid dreaming to impinge on sleep quality or produce adverse effects in those who are otherwise mentally stable, at least one recent study found that “Use of deliberate induction techniques was positively associated with psychopathology and sleep problems.”

What’s more, when participants continued with regular lucid dream induction for two months, it resulted in an increase in “dissociation and schizotypy symptoms.” According to these authors, “We conclude that lucidity should not be considered as necessarily suggestive of well-being; lucid dreaming may be positive or negative, depending on lucidity characteristics. Additionally, deliberate lucid dreaming induction may harbor negative long-term risk.”

Also, keep in mind that sleep paralysis typically occurs during REM sleep (to keep your body from acting out the dream), and if you enter a lucid state between dreaming and wakefulness, you may find yourself unable to move. This can be very distressing, depending on the nature of your dream. Once you wake up fully, the paralysis will dissipate.

Regardless of whether you feel like getting into lucid dreaming, remember that sleep is a foundational aspect of good health, and so is dreaming. Most adults need about eight hours of sleep each night, and again, your deepest REM sleep doesn’t occur until you’ve been asleep for about six hours. So, if you’re only sleeping five or six hours, you’re missing out on this important sleep cycle.

*Article originally appeared at Mercola. Reposted with permission.