Near the corner of the small, dark room, there is a narrow folding bed. Every now and then, a speaker on a nearby table emits an eerie violin riff. A line of red lights near the ceiling flashes, then flashes again, bathing the room in a lurid glow. In the bed someone who is fitted with a series of scalp and face electrodes is sleeping.
This surreal tableau is part of scientists’ effort to breach the wall between the waking world and wherever it is we are when we’re dreaming. The researchers who control the speaker and flashing lights in the lab of Ken Paller, a neuroscientist at Northwestern University, in Evanston, Ill., have been asking questions of people who are dreaming and hoping to get answers.
The dreamers have talked back in a handful of cases. Or rather, signaled back, swiveling their closed eyes back and forth or making little muscle twitches to answer arithmetic problems asked by an experimenter. A paper published this year by Paller’s team together with labs in France, Germany, and the Netherlands revealed that two-way communication with dreamers is possible. This suggests that someday, researchers may be able to ask people what they’re dreaming about while they’re still sleeping.
It’s not quite on the level of “Inception,” the 2010 movie in which Leonardo DiCaprio enters people’s dreams to steal their secrets, but it could be a way to learn more about the peculiar places we inhabit, built by our brains without our knowledge, when we lie down to sleep.
Scraps of story swimming in sensation
At the moment, the best way to get information about the alternate life we enter while sleeping is simply to wake someone up and ask if they were just dreaming. Scientists may also ask volunteers to try to dream about a given task. But there is a delay between a dream and when scientists can try to learn about it, let alone influence it. “One of the main challenges of doing dream research is that you only have access to the dream experience, the dream report, after the fact,” says Antonio Zadra, a professor of psychology at the University of Montreal.
A phenomenon called lucid dreaming offers the possibility of communication in real time. Lucid dreaming is when you realize you are dreaming but do not wake up, and instead you continue to explore your imaginary world. Lucid dreamers can control their surroundings and the narrative of their dreams to a certain extent. In the 1980s and ’90s, Stephen LaBerge, a sleep researcher then at Stanford, helped bring the subject to the mainstream, and LaBerge’s guides to dreaming lucidly sit on many a bookshelf. It is possible for some people to train themselves to dream this way, and myriad hobbyists have found themselves awake in a dreamland, able to shape it to their whims.
Researchers have found that lucid dreamers can move their closed eyes voluntarily while asleep and can signal using a prearranged rapid movement — left-right-left-right — that they’ve become lucid. The sleeper may then perform another prearranged task, like singing a song or practicing a workout in the dream and then signal again when they’ve completed it. This has allowed researchers to ask big questions. Do activities take the same amount of time in a dream as in waking life? (Yes, it appears.) Does practicing some task while dreaming improve the performance while awake? (Jury’s still out, but maybe.)
This method of experimentation can also reveal how the brain handles dreaming. When lucid dreamers trace a line with their eyes, Benjamin Baird at the University of Wisconsin and colleagues have found, they move with a smoothness they don’t have when awake and imagining the same experience. That suggests dreaming is more like a lived experience than an imagined one.
In the new study published this year, four labs around the world trained volunteers to recognize when they were dreaming. At Northwestern, the training involved lying in the bed, about to drift off, while Karen Konkoly, a graduate student who is the paper’s lead author, occasionally played the violin riff or a beeping sound or flashed the lights and asked the volunteers to practice checking if they thought they were dreaming, taking note of any strange events or perceptions. (You have eight fingers on each hand? You’re probably dreaming.) Once a person fell asleep, Konkoly watched the readings from their electrodes to see when they entered REM sleep, when many dreams happen. Then she flashed the lights or played the sounds in hopes of triggering a revelation in the dreamer.
The details of other labs’ protocols varied, but they all used established methods of inducing lucid dreaming. (Some subjects, already experienced lucid dreamers, needed no training.) Out of 36 participants across the four labs, 15 successfully signaled that they had become lucid. The experiment up to this point was much like other lucid dreaming studies, but then the researchers did something unusual — they asked the sleepers to answer math questions, like 8 minus 6, or posed other kinds of questions. Some experimenters spoke these questions, some used Morse code, and others had other methods. Six dreamers responded. When they moved their eyes or made other signals in apparent response, their movements were often ambiguous. But about half the time, they encoded the correct answer, swiveling left and right twice to indicate “2,” for instance.
After these attempts at communication, the researchers woke subjects and asked them to talk through their dreams. What they described had that familiar blend of fantastical eeriness and the strikingly mundane. One subject was fighting goblins when he realized the researchers were attempting to contact him. Another recounted, “I was in a parking lot at night . . . then suddenly it was daytime and I was in the video game.” Another found himself in a medical office: “I was alone in the room and there was a large doctor’s couch in the middle of the room, shelves, sideboards. The couch was strange . . . ” When the lights began to flash on and off, he searched for something to flash an answer back with and found a bowl full of water, which then fell from his hands and broke.
The dream reports show a complex soup of impressions, with scraps of story swimming in sensation. But subjects who answered a question confirmed that they had perceived the question in the dream, the researchers report, and some described how they had answered it by making certain movements. This suggests that at least some of the time, two-way communication is possible while a subject is asleep.
Lucid dreaming researchers knew or suspected that this was the case, says Wisconsin’s Benjamin Baird. Still, for many in the wider community of sleep researchers, the result was not a given. Studies have indicated for some time that sleepers’ brains can respond to sounds from the world around them; sleepers show distinctive brain waves at the sound of their own name, for instance. But what would happen when they were questioned in a dream state was not clear. Paller was not even sure whether the subjects would perceive the questions accurately.
“We could present words and ask questions, but these people are in a dream. They might hear totally different questions from what we ask,” he says. “We might say one question, like ‘What’s 8 minus 6?’ and they might hear ‘What’s pineapple and grapefruit?’”
The dreamers did hear the questions more or less as stated — that is, if they heard anything. Curiously, many of the lucid dreamers in the study did not realize they were being signaled to. They made the eye movement to show that they were lucid and then they did not respond to the prompts. When they woke up, they had no memory of being questioned.
A café in Paris
It is not clear why some people perceived the questions and others did not or what property of their dreams or state of consciousness might explain the difference. But staying lucid is like balancing on a knife’s edge, says Harvard sleep researcher Robert Stickgold. On the one hand, you may get so excited you’ve achieved lucidity that you wake up. On the other, you can fall back into the deep, languid waters of regular dreaming, losing the ability to participate in experiments.
That is one of the limitations inherent in questioning lucid dreamers and one of the reasons that dream researchers are cautious about what practical use the discovery may have for future research.
“There is potential to use that method in new studies to test the function of dreaming,” says Erin Wamsley, a professor of psychology who studies memory and dreaming at Furman University, in Greenville, S.C. “However, the method will always be really difficult and impractical, in the sense that you have to test dozens of participants before getting one instance of really convincing, successful communication.” Baird also points out that two-way communication isn’t necessary for many questions researchers want to ask. He suggests that understanding how sound and other information percolates into dreamers’ consciousness might be a more meaningful next step.
Still, if methods for inducing lucid dreaming were to improve and protocols for communication got easier — Paller and Konkoly are working on getting people to signal back using sniffing, which may be easier than moving their eyes — then a constellation of tantalizing little experiments might await. Do dreamers’ memories work like those of waking people? Or what happens when you close your eyes in a dream? Do you see darkness or something else? What do your brainwaves look like in those moments? Somewhere far down the road, experiments might investigate whether dreams shaped by researchers have the ability to change dreamers’ waking lives.
Zadra and Stickgold wonder about the constraints of the dreamworld itself. Transformations in dreams appear to follow certain rules. “A bus driver might turn into the milkman or into a child, but she will not turn into a book,” says Zadra. “The bus might turn into a motorcycle, but the bus is not going to turn into a bird and fly away.” Similarly, Stickgold says, if a lucid dreamer tries to teleport to a café in Paris, they may find themselves unable to do so until they pass through a doorway or turn a corner, forcing the brain to fill in a new imagined landscape — one that it can make Parisian. If researchers could ask a dreamer to meet a certain person and then signal if they succeed, or ask them speak to passersby and then signal if those people talk back, they might uncover other hidden barriers or rules governing dream construction in real time, without having to arrange the task while the dreamer is awake.
Still, the best use of this emerging method of communication may be something no one’s thought of yet.
“It definitely opens a door,” says Stickgold. “The question is, what’s on the other side?”
Veronique Greenwood is a science writer who contributes frequently to Ideas. Follow her on Twitter @vero_greenwood.