Although philosophers and scientists have written about dreams for centuries, science is only just beginning to understand how dreams work in the brain. Lucid dreaming (LD), in which the dreamer is aware that he or she is dreaming and is able to manipulate the dream, is even less well understood.
“Often during a LD, you can control dream events voluntarily, for example flying, or you can gain access to waking cognitive abilities that are not normally available, such as remembering events from the previous day," explained Tore Nielsen, the director of the Dream and Nightmare Laboratory at Montreal's Sacre-Coeur (Sacred Heart) Hospital and a professor of psychiatry at the University of Montreal, in an interview with Healthline. "In regular dreaming, you are not aware that you are dreaming, you are not usually in voluntary control of dream events, and you don't usually have access to all your waking cognitive abilities.”
A New Battleground: Dreams
This dream control might be able to help people with post-traumatic stress disorder (PTSD) overcome nightmares. These can be frightening and overwhelming for anyone, but for people with PTSD, nightmares can be a way of reliving the events that first traumatized them. Every dream seems dangerous, and sleep becomes an ordeal rather than a refuge.
“Nightmares are terrifying experiences because during regular nightmares (like regular dreams) we are unable to produce a rational judgment about its bizarreness, thus we strongly believe that what is happening during the nightmare is real,” said Dr. Sérgio Mota-Rolim, Ph.D., of the Federal University of Rio Grande do Norte in Brazil, told Healthline.
Mota-Rolim hopes that lucid dreaming might be able to help. He explained, “Psychotherapies based on inducing LD could be an effective way of treating recurrent nightmares of PTSD patients, because they—being lucid during the nightmare—would be able to: one, naturally lose their fear by realizing the absence of real threats, i.e. the lack of reality of the perceptual experience; two, simply try to wake up during the nightmare; and, three, change dream context, in a way of transforming the nightmare into a neutral or even a pleasant dream.”
There’s evidence to support this idea. One set of case studies showed that people with recurring nightmares saw their bad dreams go away after they learned lucid dreaming.
Another co-authored by Victor Spoormaker, Ph.D., found that lucid dreaming reduced the frequency and intensity of nightmares, but didn’t do anything to treat the sleep disturbance, anxiety, and depression that often accompany PTSD. “We found that LD was effective in reducing nightmare frequency, but there are a few 'but's in there,” said Spoormaker, a staff scientist at Max Planck Institute of Psychiatry in Munich, in an interview with Healthline. “One is that not everyone could learn. It is a complex treatment, one for which there are easier treatments available.”
Spoormaker recommends an alternative treatment for nightmares. “Imagery rehearsal therapy is a treatment in which the people with nightmares write down their nightmares and at some point, they will write a new ending, make a change in the nightmare itself,” he said. “Then they will rehearse this new nightmare. By imagining the new nightmare, the nightmare has a lower frequency afterwards. There’s some promising research in several PTSD populations. It is much more effective in the data than lucid dreaming treatment.”
Triggering A Lucid Dream
Lucid dreaming can be difficult to master. But if you’re wondering if there’s a shortcut, Ursula Voss, a professor at J.W. Goethe-University in Frankfurt, Germany, may have found a way. In a published earlier this month, Voss’s team discovered how to create lucid dreams by applying an electrical current to the brains of study participants while they slept.
Earlier research had identified a type of brain activity called gamma waves as being important for lucid dreaming, especially in the frontal and temporal lobes of the brain. “Gamma is usually strongly reduced in normal REM sleep dreaming. It is strongly increased in lucid dreaming,” said Voss in an interview with Healthline. “It goes along with higher-order consciousness that enables us to be self-reflective, to plan ahead and to make logical decisions.”
Voss used a method called transcranial alternating current stimulation (tACS), which can alter brainwaves without producing any side effects of stimulating the brain, such as muscle twitches or seeing bursts of color. Her team took a group of subjects with no training in lucid dreaming and then waited for them to enter REM sleep, the stage of sleep where dreaming typically occurs. Once they were in REM, the researchers applied tACS to create gamma waves in the frontal and temporal lobes of the brain. The result? Most of the subjects in the study experienced lucid dreams. The sweet spot for tACS appeared to be electric current at 25 and 40 Hz.
Montreal’s Nielsen hopes that Voss’s work will lead the way to more effective lucid dreaming therapies. “With refinements, the approach might be developed into a method that would allow scientists to explore dreaming more quickly, effectively and reliably,” he said. “If nightmare sufferers can gain some amount of control over their negative dream content, this might be therapeutically effective.”
Mota-Rolim appreciates Voss’s work but has his doubts. He points out that that used a similar type of brain simulation had only a weak effect on lucid dreaming, and worked only in experienced lucid dreamers. As for the gamma wave activity? It might be the result of the rapid eye movement that gives REM sleep its name.
His own research instead points to alpha waves in a different region of the brain, the occipital lobe. “What we found is that during LD, the occipital alpha activity reaches an intermediate level between non-lucid dreaming and waking, as if LD were a phase transition between regular dreaming and waking,” he said. “We found that for most of the people, LD is an unstable experience that usually lasts a short time, since people tend to wake up as soon as they become lucid.”
They all agree that more research is needed to understand just how lucid dreaming works. And for now? “Don't try this at home!” warns Nielsen. “Using the wrong placement of electrodes or incorrect amounts or types of electrical current could have disastrous consequences. Imagery Rehearsal Therapy is a much better option for treating nightmares at this point.”
“It’s interesting to become lucid in a dream,” said Spoormaker. “It can help to become lucid in a nightmare and then change it. But if you’re suffering from post-traumatic stress disorder, it’s better to search for an alternative treatment: image rehearsal therapy.”