When I was 19—long before I ever thought I would land a career writing about space—I dreamed I was standing on the surface of Mars, looking over a rusted desert dotted with rocks, stuck in a perpetual lukewarm dusk, transfixed by the desolation. After soaking everything in for what seemed like hours, I looked up and saw a space station hanging in the sky. I decided to fly up there using some kind of Iron Man–like jet boots on my feet. Then I woke up.
I didn’t just happen to stumble on Mars in my dream. I knew I was asleep the whole time. Engaged in what’s called “lucid” dreaming, I chose to appear on Mars. I chose to bask in the extraterrestrial solitude; I chose to go flying. And since I was having lucid dreams almost every night at the time, I experienced multiple variations of this dream—each weirder and better than the one before.
Lucid dreaming isn’t easy to describe, and the way it works varies from one person to the next. But at its core, it means being conscious of the dream state—allowing you to play a more active role. Some of my own lucid dreams were like blank canvases where I’d imagine a wild new environment and make it up as I went along. Others allowed me to process stressful situations like public speaking (I got good at making this feel casual and relaxed just by practicing in a dream). In one memorable dream I played cards with my grandmother, who’d died years earlier. The experience helped me to understand my emotions toward her in a way I never could have managed as an ornery 13-year-old.
Even when it feels as though they’re completely random, dreams have power. Aside from giving us a break from the tedious physical and social limits of the real world, they can help us process grief and make us feel more creative. But when I was lucid—a state I achieve only rarely these days—I found that I got more out of sleep. People who post their experiences with lucid dreaming in online forums often write about how it inspired new works of music or fiction, helped them brainstorm solutions to real-world problems, or simply provided weird moments of memorable amusement.
“You can make the argument that REM sleep is kind of a neglected resource,” says Benjamin Baird, a researcher at the University of Wisconsin–Madison who studies human cognition. “What if we could use this state for when people can actually have control over their thoughts and actions and decide what they want to do? The state could potentially be used for entertainment and creative problem–solving, and learning about how memory works, and all kinds of different [neuroscience].”
Baird thinks one especially intriguing application for lucid dreaming might be in art. “One technique from the visual artists I’ve met is that they find an ‘art gallery’ in their lucid dream and look at the painting hanging in the gallery,” he says. “They then wake up and paint what they saw. The same can be done analogously for hearing musical scores. It’s as if someone else is creating it, but it’s your own mind.”
A small but growing number of scientists led by Baird and other sleep labs around the world hope to learn more about how lucid dreaming works, how it’s triggered, and whether the average person can be taught how to do it regularly. By studying individuals who are able to recall what happened to them in their dreams, these researchers can correlate what cognitive processes are occurring in the mind while brain and physiological activity is being measured and observed. For example, how does the brain perceive specific objects or physical tasks taking place solely in the mind? How does it respond to visuals that aren’t really there? How does it emulate parts of consciousness without actually being fully conscious?
Some researchers, like Martin Dresler, a cognitive neuroscientist at Radboud University in the Netherlands, suggest lucid dreaming could even be used to combat clinical disorders like recurring nightmares or PTSD. “I think it’s quite intuitive and plausible that if during a nightmare you realize that it’s not real, that obviously takes much of the sort of sting out of the nightmare,” he says. You may be able to simply train yourself to wake up and end the dream, or overcome the very vivid feelings of fear and fright by telling yourself that it’s a dream.
In one memorable dream I played cards with my grandmother, who’d died years earlier. The experience helped me to understand my emotions toward her in a way I never could have managed as an ornery 13-year-old.
Why do we dream? Scientists still don’t really know. Freud thought dreams were our subconscious showing us our repressed wishes. Some evolutionary biologists believe dreaming evolved so we could play out threatening scenarios from real life and figure out how to react appropriately. Many neuroscientists who’ve studied neuronal firing during sleep believe dreams play a role in how we encode and consolidate memories. Harvard psychiatrist Allan Hobson thought dreaming was how the brain reconciled what different layers of consciousness had absorbed throughout the day.
But while dreaming itself is a robust topic of interest among researchers, lucid dreaming has historically been relegated to the fringes. Its first documented mention in Western civilization may have been in the fourth century BCE by Aristotle, in a treatise entitled “On Dreams,” where he noted that “often when one is asleep, there is something in consciousness which declares that what then presents itself is but a dream.”
Scattered anecdotal evidence of lucid dreaming would come up infrequently in scientific literature over the next two millennia, but more as a curiosity than a real scientific inquiry. In 1913, Dutch psychiatrist Frederik van Eeden coined the term “lucid dream” in an article describing a state of dreaming where one experiences “having insight.” The phenomenon was first scientifically verified in the late 1970s and 1980s, thanks mainly to Stanford University psychologist Stephen LaBerge. Scientists had known for years that sleepers’ eyes moved in the same direction as their gaze within a dream, and in a 1981 study, LaBerge gave lucid dreamers specific instructions about where to look during their dream—up and down 10 times in a row, or left to right six times, for example—and then observed their eye movements during sleep. The results showed that lucid dreamers were not just in control of their dreamscape but could execute decisions that had been outlined while they were awake. Eye movements are now the gold-standard technique researchers use to objectively verify a lucid dream state in the lab.
Perhaps the biggest breakthrough in recent years was a February 2021 study that proved lucid dreamers could conduct two-way communication with people who were awake. In a paper published in Current Biology, the researchers explained how, in four different labs around the world, they asked lucid dreamers questions (such as “What is 8 minus 6?”) by using spoken messages, beeping tones, flashing lights, or tactile stimulation. The participants would respond with specific eye movements. The researchers were, effectively, having a conversation with somebody who was asleep.
One analysis of 34 studies conducted over a half-century suggests that about 55% of all people report experiencing a lucid dream at least once in their life, and nearly a quarter have such dreams at least once a month. But there’s an extremely high degree of variability between these studies, and the vast majority of them look mainly at Westerners.
The painful truth is that lucid dreaming is poorly understood because so little research has been done—which is partly because consistent lucid dreamers are quite rare, and even more difficult to snag for a lab study. LaBerge, the closest thing to the godfather of the field, pinned down some of its common biological traits—that it occurs in the later stages of REM sleep when rapid eye movement peaks, for example. People also experienced higher respiration and heart rates during lucid dreaming than normal dreaming, suggesting that the dreamers were in a more active state. Dresler, the Dutch neuroscientist, spearheaded the only fMRI study of lucid dreaming to date in 2012, with a single subject. On the basis of those observations, he believes the phenomenon is tied to increased activation of the frontopolar cortex, which plays a role in metacognition—awareness of one’s own thought processes. He also worked on research in 2015 showing that people who are frequent lucid dreamers have more gray matter located in the frontal polar cortices.
Likewise, there’s no accepted prescription among scientists for how to trigger a lucid dream, but some interventions have shown more promise than others (see sidebar at right). Acetylcholine is the main neurotransmitter responsible for inducing REM sleep, and drugs that ramp it up—like galantamine, which is used to treat mild to moderate Alzheimer’s—have been highly successful in helping people have lucid dreams in lab studies. A trio of German and Swiss researchers are interested in using noninvasive brain stimulation techniques to induce lucid dreaming, though almost a decade on, they haven’t had much success. One informal study conducted by LaBerge suggests that trying to change light levels in a dream (say, flicking a light switch on and off) and observing a reflection in a mirror sometimes reveal that one is dreaming, since in the dream state these actions don’t work the way they do in real life.
Researchers like Baird and Dresler are constrained by the fact that most institutions don’t consider spending $500 an hour on fMRI machines to watch lucid dreamers a worthwhile investment. But they are encouraged by the fact that there’s a greater interest in dreaming studies at large. That’s especially true after reports in 2020 (including a study of dream content from around the world, published in the journal Frontiers of Psychology) suggested that pandemic lockdowns were doing weird stuff to our dreams. Some people are experiencing a heightened desire to find a bit more control over their lives, and that includes dreaming. I’d certainly count myself among them.
Neel V. Patel is MIT Technology Review’s space reporter.