Scientists asked lucid dreamers math questions. Some answered

Imagine being able to communicate well enough with someone who's dreaming that you can ask them to solve a math problem —and they give the right answer. It might sound far fetched, but according to a recent study that combines the work of four independent labs, this is not science fiction.

The experiments took advantage of the phenomenon of lucid dreaming, which occurs when a person who's dreaming becomes aware that they're in a dream. They can in some cases then control aspects of the dream.

In the study published in the journal Current Biology, the scientists wrote, "Our experimental goal is akin to finding a way to talk with an astronaut who is on another world, but in this case the world is entirely fabricated on the basis of memories stored in the brain."

Scientists have known for several decades that lucid dreamers can communicate out to the real world from inside their dreams. The most cited method in this kind of research is to communicate through eye movements.

When you move your eyes in your dream world, the actual eyes in your body move."- Prof. Ken Paller, Northwestern University

"During a dream, your body is quite paralyzed, but your eyes move freely. And when you move your eyes in your dream world, the actual eyes in your body move, and we can record that quite easily with electrodes," said Professor Ken Paller, the director of the cognitive neuroscience program at Northwestern University.

"The unknown was — can we communicate in, effectively enough, to have a conversation? And that's what we did in this study," said Paller. 

Prior studies done with people who have regular dreams also suggest their brains can process information in a way that looks like they're responding to queries from the outside world.

Triggering a lucid dream

"It's a difficult phenomenon to create; it's not like you can make it happen every time," Paller said in an interview with Quirks & Quarks host, Bob McDonald. 

One of the study's test subjects, a 20-year-old in France with narcolepsy, had "remarkable lucid-dreaming abilities," the scientists wrote.

Others in the study — 36 in total from the four labs in the United States and Europe — were either experienced lucid dreamers or those who'd never had a lucid dream before.

The researchers trained the participants by playing a soft audio cue, like a violin sound, while they were awake. As the sound was played the scientists instructed the volunteers to to pay attention to their surroundings and ask themselves: "Is this experience any different than your normal waking experience?" 

Once in REM sleep, the researchers would then play the same audio cue for the participants to cue them to check their environment to see whether or not they were in a dream or awake. 

Integrating the cue in their dreams

Christopher Mazurek, a Northwestern University student, had his first lucid dreaming experience as a test subject in Paller's lab. 

He said that, "culture shock isn't the right word to use, but it was just so different, such an odd, intense, amazing feeling that was so different from normal life."

It wasn't until his third lucid dream that he managed to answer the researcher's questions. 

Our interesting conclusion is that it's possible to make it happen.- Prof. Ken Paller, Northwestern University

In that dream, he said he was viewing himself as the protagonist in the Legend of Zelda video game from a third person perspective.

"The cue came kind of as a sound in the video game," he recalled.

Once the dreamers in the lab became aware inside their dream and entered into a lucid state, they were instructed to signal to the researchers by looking all the way to the left and all the way to the right twice. The eye movement was visible to the researchers. 

"After I signaled that I was lucid, they played a math problem for me in my dream, which was eight minus six. And to answer the math problem, I did two left-right eye movements to correspond to the number two, which is the signal that we had worked out before," explained Mazurek.  He was the first in Paller's lab to successfully accomplish the task. 

"We thought we were the first ones in the world to have ever done that at that point," said Paller.

But as he soon discovered, his lab in Chicago wasn't the first to establish two-way communication with a lucid dreamer. 

Scientists in a lab in Germany had previously done a similar study, but hadn't published their research yet. 

Then Paller found out that scientists in the Netherlands and in France were also studying two-way communication with lucid dreamers, so in the end the four labs decided to collaborate and combine their findings into a single study.

They sent their data, which included brain wave readings taken during the experiment, to three independent experts in Paris who evaluated their findings to validate that the lucid dreamers were, in fact, answering from within REM sleep. 

Proof of concept to potential future uses

In total, out of 36 participants in all four labs, the researchers were only able to establish two-way communication with six of them, and only got correct answers 18 per cent of the time out of a total of 154 attempts.

"So our interesting conclusion is that it's possible to make it happen (...) and now we're working on methods to make it happen more frequently," said Paller.

He expects this could help better understand "why we dream, what dreams are useful for, how they influence our waking activity, our memory, our creativity, our problem-solving, maybe even our wellbeing." 

Since disorders like PTSD, anxiety and depression are often also associated with difficulties sleeping, Paller wonders if real time communication through lucid dreaming could also have a therapeutic value. 

"We are now looking at how you could actually change what's happening during sleep and see if that could promote more healthy behaviours when you wake up," he said.

Produced and written by Sonya Buyting