Scientists entered people’s dreams and made them ‘talk’ | Science

By Sofia MoutinhoFeb. 18, 2021 at 11:05 am

In the movie Creation, Leonardo DiCaprio enters the dreams of others to interact with them and steal secrets from their subconscious. Now, it looks like this sci-fi storyline is one more step towards reality. For the first time, researchers had “conversations” involving new questions and math problems with lucid dreamers – people who are aware that they are dreaming. The results, from four labs and 36 participants, suggest that people can receive and process complex external information while they sleep.

“This work challenges fundamental definitions of sleep,” says cognitive neuroscientist Benjamin Baird of the University of Wisconsin, Madison, who studies sleep and dreams but is not part of the study. Traditionally, he says, sleep has been defined as a state in which the brain is disconnected and unaware of the outside world.

Lucid dreaming got one of its first mentions in the writings of the Greek philosopher Aristotle in the fourth century BCE, and scientists have observed it since the 1970s in experiments on the rapid eye movement (REM) phase. of sleep, when most dreams occur. One in two people have had at least one lucid dream, about 10% of people experience it once a month or more. Although rare, this ability to recognize that you are in a dream – and even to control certain aspects of it – can be improved with training. A few studies have attempted to communicate with lucid dreamers by using stimuli such as lights, shocks, and sounds to “enter” into people’s dreams. But these recorded only minimal responses from sleepers and did not involve complex transmission of information.

Four independent teams in France, Germany, the Netherlands and the United States attempted to go further and establish complex two-way communication during dreams, using speech and asking questions that sleepers do. ‘had never heard in their training. They recruited 36 volunteers, including some experienced lucid dreamers and others who had never experienced a lucid dream before but remembered at least one dream per week.

The researchers first trained the participants to recognize when they were dreaming, by explaining how lucid dreaming works and by demonstrating signals – sounds, lights, or finger tapping – that they would present while the dreamers slept. The idea was that these signals signaled to the participants that they were dreaming.

The nap sessions were scheduled at different times: some at night, when people went to bed regularly, and others early in the morning. Each lab used a different way of communicating with the sleeper, from oral questions to flashing lights. Sleepers were told to report that they had entered a lucid dream and to answer questions by moving their eyes and face in special ways, such as moving their eyes three times to the left.

As the participants fell asleep, the scientists monitored their brain activity, eye movements and facial muscle contractions – common indicators of REM sleep – with EEG headsets fitted with electrodes. Out of a total of 57 sleep sessions, six people reported lucid dreaming in 15 of them. In these tests, researchers asked dreamers simple yes or no questions or math problems, like eight minus six. To respond, the dreamers used cues they were taught before falling asleep, including smiling or frowning, moving their eyes multiple times to indicate a nap, or, in the German lab, moving their eyes in matching patterns. to Morse code.

The researchers asked lucid dreamers 158 questions, who answered correctly 18.6% of the time, report researchers today in Current biology. Dreamers gave the wrong answer to only 3.2% of the questions; 17.7% of their answers were not clear and 60.8% of the questions were not answered. Researchers say these numbers show that communication, even if difficult, is possible. “It’s a proof of concept,” Baird says. “And the fact that different labs have used all of these different ways to prove that it’s possible to have this kind of two-way communication … makes it stronger.”

After several questions, the dreamers were woken up and asked to describe their dreams. Some recalled the questions in a dream: A dreamer reported math problems coming out of a car stereo. Another was at a party when he heard the researcher interrupt his dream, like a narrator in a movie, to ask if he spoke Spanish.

The experiment offers a better way to study dreams, says lead author Karen Konkoly, cognitive neuroscientist at Northwestern University. “Almost everything that is known about dreams is based on historical records given while the person is awake and these can be distorted.” Konkoly hopes that this technique can be used in the future for therapeutic purposes to influence people’s dreams so that they can better cope with trauma, anxiety and depression.

Sleepy “conversations” can also help the dreamer solve problems, learn new skills, or even come up with creative ideas, Baird says. “Dreaming is a highly associative state which can have advantages in terms of creativity.”

Michelle Carr, a cognitive neuroscientist at the University of Rochester, who was not involved in the study, says she is excited about such future applications. But she stresses that retrospective reporting on dreams cannot be replaced. “When you’re in a dream, your reporting skills are quite limited,” she says.

Changing people’s thoughts during dreams is still science fiction, points out co-author and cognitive neuroscientist Ken Paller, also at Northwestern. Nevertheless, he thinks that experience is an important first step in communicating with dreamers; he compares it to the first conversation using a telephone or to a conversation with an astronaut on another planet. Dreamers live in a “world made up entirely of memories stored in the brain,” he says. Now, researchers seem to have found a way to communicate with the people of this world.