Four independent experiments across the globe have found that it's possible to establish two-way communications with people in the weird, hallucinatory state of lucid dreaming, opening up a new field of real-time "interactive dreaming" research.
This is a big deal for scientists trying to work out what the heck is going on as we sleep, because typically they've had to rely on the fragmented, fading scraps of memory people have once they've woken up. "Our experimental goal is akin to finding a way to talk with an astronaut who is on another world," reads the introduction of a combined study between four separate groups in France, Germany, the Netherlands and the USA.
Each group set out to test its own techniques on how to "interview" people without waking them up, using the bizarre phenomenon of lucid dreaming as a doorway into the dream world. During regular dreams, we typically have no idea that we're dreaming, simply accepting the strange situations we're placed in without critical judgement. Lucid dreaming, a "notoriously rare phenomenon," is a state where the sleeper is aware that they're dreaming, and sometimes capable of steering their experience.
The researchers took one group of experienced lucid dreamers, another of regular folk that they had trained in the art of lucid dreaming, and one patient with narcolepsy who frequently drifted in and out of lucid dream states – and found they were able to have two-way exchanges with members of all three groups.
In all the tests, the scientists verified that each subject was in a state of REM sleep, using "standard polysomnographic methods." Facial and eye movements were chosen as the means by which the dreamers could "talk back" to the researchers from the dream world, and the subjects were trained in specific ways of communicating. Some, for example, were trained to move their eyes left to right three times (LRLRLR) in response to an audio cue if they wanted to communicate that they were in the lucid dream state. None were trained with the specific questions they'd be asked when they were asleep.
From there, the USA team from Northwestern University started getting the dreamers to answer maths questions asked verbally by the researchers, with an appropriate number of left-right eye movements scanning all the way left to right, which made the correct answers stand out clearly from the regular levels of eye movement in REM sleep.
The Dutch team from Radboud University Medical Center went for something similar, adding some visual cues as well. The German team from Osnabrück University also gave its dreamers math questions, this time in the form of morse code and alternating colors, with left-right eye movements as the answer.
The French team, from Sorbonne University, working with the narcoleptic subject, was able to ask verbal yes/no questions. The subject answered yes by contracting his zygomatic muscles, which draw the sides of the mouth up and out like a broad smile, and no by contracting his corrugator muscles, the ones we use to furrow our eyebrows. Another subject was asked to count how many times the researcher was tapping his right hand.
Across 158 attempts to communicate with lucid dreamers across all teams, the researchers got correct responses 18.4% of the time, incorrect responses 3.2% of the time, inconclusive answers 17.7% of the time and no response 60.1% of the time.
After the subjects woke up, they were interviewed about what had just happened, and most of the time, they remembered the communications. Some said the questions came through as if they were from outside the dream, or superimposed over it. "I was at a party with friends," said one subject, "Your voice was coming from the outside, just like a narrator of a movie."
"During the finger tapping," said another subject with a particularly vivid inner life, "I was fighting against goblins. I remember being surprised that I was able to do many things at the same time as the task."
Other times, the questions were incorporated into the dreams, the researcher's voice coming through a radio, for example, or the dream otherwise morphing to find logical ways to include the outside stimulus.
While the subjects mostly remembered the interactions, they often got details wrong when they reported what they'd been asked. They might remember that they were asked a math question, for example, but get the numbers wrong – and this, say the researchers, highlights just how unreliable any waking memories of dreams can be.
The research establishes that under certain circumstances, it's possible to send messages into somebody's dream, and for them to listen, calculate an answer and reply. Subjects were able to remember pre-sleep instructions on how to answer questions, and to correctly answer questions about their waking life like "do you speak Spanish?"
"We’ve long known that cognition and consciousness are not shut off during sleep," reads the study, "but our results now broaden the opportunities for empirically peering inside the sleeping mind. The advent of interactive dreaming—with new opportunities for gaining real-time information about dreaming, and for modifying the course of a dream—could usher in a new era of investigations into sleep and into the enigmatic cognitive dimensions of sleep."
Where to from here? The researchers say this "interactive dreaming" research should open up a whole bunch of new research avenues, including testing out the ability to steer the content of somebody's dream from the outside. This might include dreams "curated in accordance with an individual's objectives, such as to practice a musical or athletic skill," or therapeutic dreams to "lessen the impact of emotional trauma," with real-time feedback from the subject.
There could also be sessions designed for problem-solving, using the dream state as a different perspective on problems, or for interactive "moonshot" sessions attempting to "combine the creative advantages of dreaming with the logical advantages of wake." Artists and writers, say the researchers, "might also gain inspiration from sleep communication."
The paper is available free in Current Biology.
Source: Eurekalert!
