Can lucid dreaming help us understand consciousness?

David Robson
Sun 14 Nov 2021 02.00 EST

This article is a repost which originally appeared on The Guardian

Edited for content.

The ability to control our dreams is a skill that more of us are seeking to acquire for sheer pleasure. But if taken seriously, scientists believe it could unlock new secrets of the mind

Michelle Carr is frequently plagued by tidal waves in her dreams. What should be a terrifying nightmare, however, can quickly turn into a whimsical adventure – thanks to her ability to control her dreams. She can transform herself into a dolphin and swim into the water. Once, she transformed the wave itself, turning it into a giant snail with a huge shell. “It came right up to me – it was a really beautiful moment.”

There’s a thriving online community of people who are now trying to learn how to lucid dream. (A single subreddit devoted to the phenomenon has more than 400,000 members.) Many are simply looking for entertainment. “It’s just so exciting and unbelievable to be in a lucid dream and to witness your mind creating this completely vivid simulation,” says Carr, who is a sleep researcher at the University of Rochester in New York state. Others hope that exercising skills in their dreams will increase their real-life abilities. “A lot of elite athletes use lucid dreams to practise their sport.”

And there are more profound reasons to exploit this sleep state, besides personal improvement. By identifying the brain activity that gives rise to the heightened awareness and sense of agency in lucid dreams, neuroscientists and psychologists hope to answer fundamental questions about the nature of human consciousness, including our apparently unique capacity for self-awareness. “More and more researchers, from many different fields, have started to incorporate lucid dreams in their research,” says Carr.

This interest in lucid dreaming has been growing in fits and starts for more than a century. Despite his fascination with the interaction between the conscious and subconscious minds, Sigmund Freud barely mentioned lucid dreams in his writings. Instead, it was an English aristocrat and writer, Mary Arnold-Forster, who provided one of the earliest and most detailed descriptions in the English language in her book Studies in Dreams.

Published in 1921, the book offered countless colourful escapades in the dreamscape, including charming descriptions of her attempts to fly. “A slight paddling motion by my hands increases the pace of the flight and is used either to enable me to reach a greater height, or else for the purpose of steering, especially through any narrow place, such as through a doorway or window,” she wrote.

Based on her experiences, Arnold-Forster proposed that humans have a “dual consciousness”. One of these, the “primary self”, allows us to analyse our circumstances and to apply logic to what we are experiencing – but it is typically inactive during sleep, leaving us with a dream consciousness that cannot reflect on its own state. In lucid dreams, however, the primary self “wakes up”, bringing with it “memories, knowledge of facts, and trains of reasoning”, as well as the awareness that one is asleep.

She may have been on to something. Neuroscientists and psychologists today may balk at the term “dual consciousness”, but most would agree that lucid dreams involve an increased self-awareness and reflection, a greater sense of agency and volition, and an ability to think about the more distant past and future. These together mark a substantially different mental experience from the typically passive state of non-lucid dreams.

“There’s a grouping of higher-level features, which seem to be very closely associated with what we think of as human consciousness, which come back in that shift from a non-lucid to a lucid dream,” says Dr Benjamin Baird, a research scientist at the Center for Sleep and Consciousness at the University of Wisconsin-Madison. “And there’s something to be learned in looking at that contrast.”

You may wonder why we can’t just scan the brains of fully awake subjects to identify the neural processes underlying this sophisticated mental state. But waking consciousness also involves many other phenomena, including sensory inputs from the outside world, that can make it hard to separate the different elements of the experience. When a sleeper enters a lucid dream, nothing has changed apart from the person’s conscious state. As a result, studies of lucid dreams may provide an important point of comparison that could help to isolate the specific regions involved in heightened self-awareness and agency.

Unfortunately, it has been very hard to get someone to lucid dream inside the noisy and constrained environment of an fMRI scanner. Nevertheless, a case study published in 2012 confirmed that it can be done. The participant, a frequent lucid dreamer, was asked to shift his gaze from left to right whenever he “awoke” in his dream – a dream motion that is also known to translate to real eye movements. This allowed the researchers to identify the moment at which he had achieved lucidity.

The brain scans revealed heightened activity in a group of regions, including the anterior prefrontal cortex, that are together known as the frontoparietal network. These areas are markedly less active during normal REM sleep, but they became much busier whenever the participant entered his lucid dream – suggesting that they are somehow involved in the heightened reflection and self-awareness that characterise the state.

Several other strands of research all point in the same direction. Working with the famed consciousness researcher Giulio Tononi, Baird has recently examined the overall brain connectivity of people who experience more than three lucid dreams a week. In line with the findings of the case study, he found evidence of greater communication between the regions in the frontoparietal network – a difference that may have made it easier to gain the heightened self-awareness during sleep.

Further evidence comes from the alkaloid galantamine, which can be used to induce lucid dreams. In a recent study, Baird and colleagues asked people to sleep for a few hours before waking. The participants then took a small dose of the drug, or a placebo, before practising a few visualisation exercises that are also thought to modestly increase the chances of lucid dreaming. After about half an hour, they went back to sleep.

The results were striking. Just 14% of those taking a placebo managed to gain awareness of their dream state, compared with 27% taking a 4mg dose of galantamine, and 42% taking an 8mg dose. “The effect is humongous,” says Baird.

Galantamine has been approved by Nice to treat moderate Alzheimer’s disease. It is thought to work by boosting concentrations of the neurotransmitter acetylcholine at our brain cell’s synapses. Intriguingly, previous research had shown that this can raise signalling in the frontoparietal regions from a low baseline. This may have helped the dreaming participants to pass the threshold of neural activity that is necessary for heightened self-awareness. “It’s yet another source of evidence for the involvement of these regions in lucid dreaming,” says Baird, who now hopes to conduct more detailed fMRI studies to test the hypothesis.

Prof Daniel Erlacher, who researches lucid dreams at the University of Berne in Switzerland, welcomes the increased interest in the field. “There is more research funding now,” he says, though he points out that some scientists are still sceptical of its worth.

That cynicism is a shame, since there could be important clinical applications of these findings. When people are unresponsive after brain injuries, it can be very difficult to establish their level of consciousness. If work on lucid dreams helps scientists to establish a neural signature of self-awareness, it might allow doctors to make more accurate diagnoses and prognoses for these patients and to determine how they might be experiencing the effects of their illness.

At the very least, Baird’s research is sure to attract attention from the vast online community of wannabe lucid dreamers, who are seeking more reliable ways to experience the phenomenon. Galantamine, which can be extracted from snowdrops, is already available as an over-the-counter dietary supplement in the US, and its short-term side-effects are mild – so there are currently no legal barriers for Americans who wish to self-experiment. But Baird points out that there may be as-yet-unknown long-term consequences if it is used repeatedly to induce lucid dreams. “My advice would be to use your own discretion and to seek the guidance of a physician,” he says.

For the time being, we may be safest using psychological strategies (see below). Even then, we should proceed with caution. Dr Nirit Soffer-Dudek, a psychologist at Ben-Gurion University of the Negev in Israel, points out that most attempts to induce lucid dreaming involve some kind of sleep disturbance – such as waking in the middle of the night to practise certain visualisations. “We know how important sleep is for your mental and physical health,” she says. “It can even influence how quickly your wounds heal.” Anything that regularly disrupts our normal sleep cycle could therefore have undesired results.

Many techniques for lucid dream induction also involve “reality testing”, in which you regularly question whether you are awake, in the hope that those thoughts will come to mind when you are actually dreaming. If it is done too often, this could be “a bit disorienting”, Soffer-Dudek suggests – leading you to feel “unreal” rather than fully present in the moment.

Along these lines, she has found that people who regularly try to induce lucid dreams are more likely to suffer from dissociation – the sense of being disconnected from one’s thoughts, feelings and sense of identity. They were also more likely to show signs of schizotypy – a tendency for paranoid and magical thinking.

Soffer-Dudek doubts that infrequent experiments will cause lasting harm, though. “I don’t think it’s such a big deal if someone who is neurologically and psychologically healthy tries it out over a limited period,” she says.

Perhaps the consideration of these concerns is an inevitable consequence of the field’s maturation. As for my own experiments, I am happy to watch the research progress from the sidelines. One hundred years after Mary Arnold-Forster’s early investigations, the science of lucid dreaming may be finally coming of age.

How to lucid dream

There is little doubt that lucid dreaming can be learned. One of the best-known techniques is “reality testing”, which involves asking yourself regularly during the day whether you are dreaming – with the hope that this will spill into your actual dreams.

Another is Mnemonic Induction of Lucid Dreaming (Mild). Every time you wake from a normal dream, you spend a bit of time identifying the so-called “dream signs” – anything that was bizarre or improbable and differed from normal life. As you then try to return to sleep, you visualise entering that dream and repeat to yourself the intention: “Next time I’m dreaming, I will remember to recognise that I’m dreaming.” Some studies suggest that it may be particularly effective if you set an alarm to wake up after a few hours of sleep and spend a whole hour practising Mild, before drifting off again. This is known as WBTB – Wake Back to Bed.

There is nothing particularly esoteric about these methods. “It’s all about building a ‘prospective’ memory for the future – like remembering what you have to buy when you go shopping,” says Prof Daniel Erlacher.

Technology may ease this process. Dr Michelle Carr recently asked participants to undergo a 20-minute training programme before they fell asleep. Each time they heard a certain tone or saw the flash of a red light, they were asked to turn their attention to their physical and mental state and to question whether anything was amiss that might suggest they were dreaming. Afterwards, they were given the chance to nap, as a headset measured their brain’s activity. When it sensed that they had entered REM sleep, it produced the same cues as the training, which – Carr hoped – would be incorporated into their dreams and act as reminders to check their state of consciousness. It worked, with about 50% experiencing a lucid dream.

Some commercial devices already purport to offer this kind of stimulation – though most have not been adequately tested for their efficacy. As the technology advances, however, easy dream control may come within anyone’s reach.

David Robson is a writer based in London. His next book, The Expectation Effect: How Your Mindset Can Transform Your Life (Canongate), is available to preorder now