Heal yourself from inside your dreams

I WAS scrambling away from a monstrous dark figure when I started to have the sneaking feeling that I had been here before, running from this man. I realised that I was in a bad dream, one I’d had several times recently. Only this time, I stopped mid-stride and turned around to face my attacker. “Who are you?” I screamed. “What do you want?”

I was in a lucid dream, a state of consciousness in between waking and sleeping, in which people are in a dream world but remain aware and able to control their actions. I normally use the dreams for fun – flying, say, or exploring – but sometimes I become lucid within bad dreams or nightmares. At first, I would simply wake myself up whenever this happened, but over time I realised I could change the dreams from within.

Psychologists have long been interested in using dreams to rewrite nightmares or help people overcome persistent fears. But the ability to use lucid dreams has been limited because they are difficult to trigger, and, as with all dreams, memories of them evaporate so quickly upon waking.

That could be about to change, however, as more consistent ways to induce these dreams are uncovered. It is even becoming possible to communicate with the dreamer and record what’s happening within dreams. These advances raise the tantalising prospect of unlocking this unique state of mind to create therapies for people with nightmares, anxiety and other conditions. We may soon be able to treat people within their dreams.

I learned to lucid dream several years ago, initially by accident. When I went to bed or as I woke up, I would often get caught in a scary half-awake state where I was alert but unable to move or speak – something called sleep paralysis. To get out of this, I found it easier to fall back asleep than force myself awake. Since I maintained some awareness while drifting off, this often resulted in a lucid dream. It turns out that what I was doing isn’t so different from techniques used to induce lucid dreams deliberately (see “I can control a computer with my mind – from inside a dream“).

People have been experiencing and writing about lucid dreams for thousands of years. Now with the advent of brain imaging, we have been able to learn much more about what goes on during them. Comparing the brain scans of people who were awake, asleep or in lucid dreams revealed what many had long suspected: lucid dreaming is a state in between REM sleep – the phase in which most of our dreams occur – and waking. Unlike regular dreams, lucid dreams involve brain activity in areas associated with working memory and regions thought to play a role in higher cognitive functions, such as planning and behavioural control.

“It’s a step toward conveying the content of dreams to the outside world – in real time”

Dreams have long been a focus of psychological therapy, for many reasons. Recurring nightmares can be symptomatic of anxiety, post-traumatic stress disorder and other conditions. Discussing dreams during therapy can provide an insulated way for people to explore traumatic subjects, and attempting to rewrite them can help overcome phobias or grief. For this, patients are encouraged to use a strategy known as imagery rehearsal therapy, in which they rehearse and then try to play out challenging scenarios within their dreams, or change the course of nightmares.

The first hints that lucid dreaming could enhance or even expand on the therapeutic use of dreams came in the past decade, when psychologists found that people who are capable of lucid dreaming may be more resilient to trauma and better able to avoid nightmares. Then, in 2015, Brigitte Holzinger and colleagues at the Institute for Consciousness and Dream Research in Vienna, Austria, showed that lucid dreaming makes therapy for nightmares more effective.

When Holzinger asked people undergoing a variation of imagery rehearsal therapy to try lucid dreaming, those who were successful stopped fearing sleep and began to enjoy their dreaming lives. One person even figured out how, within a nightmare, to go back to a point before a threat had started and continue the dream in another direction. People also found that lucid dreams brought a sense of power and control that translated into waking life, a welcome change from the helplessness often experienced in nightmares. This outcome is the ideal for this kind of therapy: to enable people to confront the source of their trauma or anxiety by directing or changing the course of their dreams.

But the utility of strategies like these is limited by how well people can learn to lucid dream. Even with the best existing methods, results are spotty. Now, though, researchers have found a way to induce such dreams.

In 2014, Ursula Voss and her colleagues at Goethe University Frankfurt in Germany discovered that a technique known as transcranial alternating current stimulation could spur lucidity in dreams. It involves applying a low electrical current to the brain’s frontal cortex during REM sleep, and it works about two-thirds of the time. “Stimulating the frontal area is like putting ‘wake’ activity into sleep,” says Cloé Blanchette-Carrière at the Dream and Nightmare Laboratory in Montreal, Canada.

Blanchette-Carrière is interested in therapies that would trigger lucid dreams instead of relying on people teaching themselves to induce them. “We want to apply this to nightmare sufferers or PTSD patients, to make them able to modify or control their dreams,”she says. She already has promising results from a preliminary study.

The next hurdle in using lucid dreams as a treatment is to communicate with someone once they are asleep, to provide external support as they face a source of trauma, for instance. Many of us have experienced incorporating a noise from the waking world into a dream – a horn honking outside, or music playing on a nearby radio, for instance. But can we deliberately send messages into people’s dreams?

To find out, Kristoffer Appel, a sleep and dream researcher at Osnabrück University in Germany, recruited experienced lucid dreamers and monitored their brain waves and eye movements as they slept. When in lucid dreams people are capable of moving their eyes deliberately, so Appel instructed his volunteers to let him know when they were lucid by looking left-right, left-right. Once he got the cue, he tried to send signals into their dreams using audio tones and flashing lights.

Hello in there

Of 10 volunteers, seven reported incorporating the sounds or lights into their dreams. The tone might become a noise from a ship, car or cellphone. Some people registered the flashing lights as the whole dream turning bright and dark; for others, it was the lightning in a thunderstorm, or a lamp that switched on and off. Those who noticed the noises or lights realised that they were messages from the waking world.

But Appel wanted to go further: he wanted to send more complex messages, and he wanted the dreamers to respond. So he asked these same volunteers to learn basic Morse code for numbers. The idea was to use a series of audio tones to send the dreamers simple arithmetic problems, like 3 + 5 or 7 – 2. The dreamers didn’t know the numbers in advance, and were told to answer using Morse code eye signals. For instance, a “3” in Morse code is three short and two long dashes, so the subject would look three times to the left and two times to the right.

For Appel and the volunteers, it felt like there was a lot at stake. Many people who can lucid dream have spent months, if not years, teaching themselves how. Although confident it would be possible to communicate from within their dreams, the volunteers feared they might let the side down by waking too soon or failing to find the signals. But it worked, at least for three of them: they not only got the signals, but gave the correct answers. One participant described how he looked around his dream for something that might convey signals from outside. He was in a bus terminal, and spotted a ticket machine. Soon, it began to beep. “I was thrilled to bits… I decoded the first message, confirmed the numbers, solved the math problem, and answered it back to the wak[ing] world: 4 + 4 = 8. I next walked along the street further, telling other pedestrians that I was solving tasks within a lucid dream.”

Relying on eye movements limits how much information can be conveyed, however. So Remington Mallett, a researcher then at the University of Missouri–St Louis, decided to try using a brain-computer interface, a device that – as the name suggests – enables the brain to talk directly to an external device such as a computer. Mallett believed lucid dreamers should be able to use it, since there is an overlap in the way the brain treats activities during lucid dreams and waking. When lucid dreamers imagine clenching a fist, for example, activity in the brain’s motor cortex and even muscle twitches in the wrist of that hand can be detected.

To see whether controlling a brain-computer interface from inside a dream was possible, Mallett recruited two self-taught lucid dreamers to try a simple headset, the Emotiv Epoc. It maps the activity of the brain, and then uses these signals to direct different desired outcomes on the computer. So if you imagine moving the cursor on a screen, it moves. “You basically move virtual objects with your mind,” says Mallett, like a “Jedi mind trick”.

First, Mallett trained the volunteers – awake and lying down with their eyes closed – to move a block on a computer screen using only their minds. Once they reached 75 per cent accuracy, they were ready to try the task during sleep. When they became lucid, they let Mallett know with quick left-right eye movements, and then began the task. Mallett saw the signal from both volunteers, and then the block steadily moved forward on the screen.

One volunteer said that during the waking task, he was imagining a street fighter character moving the block forward. During the dream he did the same thing. So in his sleeping mind was him as the dreamer, and in the dreamer’s mind was the mental image of a little ninja moving the block. “It’s fairly meta,” says Mallett. “You’re imagining about imagining something. We’re taking this mental cognitive task and observing it objectively.” It’s a first step toward being able to convey the content of dreams to the outside world, in real time.

“Imagine halting a recurring nightmare by choosing a different ending”

This approach could also help people learn how to control prosthetic limbs. Like moving blocks on the screen, a brain-computer interface can pick up activity in the motor cortex when you imagine moving your arm, sending the signals to the prosthesis. These devices have even been used to restore brain-controlled walking in people who have had a spinal cord injury.

People with lower limb paralysis who must learn to control an exoskeleton face an added barrier, in that the brain may forget how to send motor signals to their legs. In August, the Walk Again Project – an international collaboration led by Miguel Nicolelis at Duke University in Durham, North Carolina – helped people with partial paralysis regain some muscle control in their lower limbs. To do so, they first learned to use brain activity to control an avatar in virtual reality, getting it to walk around a field. This helped the brain relearn how to send motor signals, which meant that when people moved on to using a real exoskeleton they got the hang of controlling it more quickly. With lucid dreaming, people could exercise their mental muscles in their dream world every night, helping them eventually transition to controlling a real exoskeleton.

As well as the many therapeutic applications, looking into our lucid dreams could also enable us to harness our creativity. Many people find inspiration in their sleep. The melody for Yesterday came to Paul McCartney while he was dreaming, and Dmitri Mendeleev famously dreamed up the structure of the periodic table of elements. But as we know, when inspiration strikes in this way it is a race to jot it down once you wake up.

New gadgets, like the headset in Mallett’s study, could eventually be used to help us record ideas from within lucid dreams. And Appel is developing a sleep mask that could record eye-movement Morse code for people to transfer messages. He is also experimenting with something more of us are familiar with: texting. “We are trying for dreamers to just follow the keys with their eyes and track the movements.”

As techniques for inducing and communicating from within lucid dreams improve, the possibilities will only grow. For mental health professionals and those who study sleep disorders, the potential for psychological therapies is most inspiring. Imagine, after prolonged grief, getting to say the final goodbye you hadn’t been able to. Imagine overcoming a persistent fear while receiving messages of support from the waking world, or halting a recurring nightmare by choosing a different ending. As Blanchette-Carrière says, “If people are able to control the dream, they will be empowered to modify their behaviour in real life.”

This article appeared in print under the headline “It was just a dream…”