Researchers have managed to communicate with “lucid dreamers”. A first that calls into question the belief that REM sleep is a state in which we are cut off from the world.
- A dreamer has been able to respond to a number of stimuli while asleep.
- The possibility of communicating with a dreamer opens up perspectives for identifying physiological markers of consciousness, dreams and decoding the activity of our brain during the dream experience.
When we dream, we are at first sight cut off from the world. But for the first time, a collaboration between researchers from Inserm, AP-HP, Sorbonne University and CNRS shows that two-way communication, from the experimenter to the dreamer and vice versa , is possible during the dream. These results, published in Current Biologyopen the way to a better scientific understanding of dreams and sleep.
Why do we dream? What exactly are we dreaming of? What happens in our brain during this mysterious experience? These are all questions that fascinate researchers in neuroscience and which are particularly difficult to answer. Indeed, scientific knowledge of dreams today is mainly based on the dreamer’s account of them when he wakes up. Memory, self-censorship or storytelling biases are therefore possible.
How to communicate with someone asleep?
To advance research on this point, scientists have therefore turned to “lucid dreamers”, individuals aware of dreaming when they dream and, for some, capable of influencing the scenario of their dream. Studies have shown in particular that these dreamers were able to inform of their lucidity and therefore of the beginning and end of a predefined task carried out in dream (for example, to hold one’s breath), thanks to a previously learned ocular code. This communication was however one-way, only the dreamer being able to send the signal that he is aware of dreaming.
“The idea of two-way communication might seem like an unattainable ambition. How do you communicate with someone asleep? But if we showed that it was possible, fascinating new avenues opened up for study. of the dream”, explains Delphine Oudiette, Inserm researcher at the Brain Institute (Inserm/AP-HP/Sorbonne University/CNRS).
The team first called on a very experienced lucid dreamer to try to establish this double communication. The researchers used different types of stimulation, such as open-ended questions asked aloud: “Do you like this or that?”, tactile stimuli (tapping the hand to count) or even semantic discrimination tasks (distinguishing between simple words like “high”, “low”…). The sleeping subject then had to answer these questions by contracting the muscles of his face (eg smiling to say ‘yes’ and frowning to say ‘no’).
A “divine voice”
The results of these experiments suggest that the subject was able to respond to a number of these stimuli while asleep. Upon awakening, he further reported that the experimenter’s voice came as a “divine voice” right in the middle of his dream, in which he was partying with friends.
“So we had a first proof that a dialogue with a dreamer is possible. We then realized that several other laboratories in the world were conducting similar experiments. In our team, we conduct our studies with narcoleptic subjects[1]because their access to REM sleep, during which lucid dreaming occurs, is privileged, but others carry out their experiments on subjects without sleep disorders”, continues Delphine Oudiette.
Different groups – French, American, German and Dutch – have therefore decided to pool their data, obtained from studies carried out independently. This collaboration allowed them to confirm that it is possible to have a real exchange between an awake person and a sleeping person during the dream. In the various studies, the subjects were for example able to answer the questions of the experimenters (for example to mental calculation exercises) by means of an ocular code or the contraction of the facial muscles. By combining these tasks with electrophysiological recordings, the researchers showed that the dreamers were always in REM sleep when answering the questions.
“These works challenge the idea that we are completely cut off from the world during sleep, unable to receive or send information to our environment”, conclude the researchers. “The possibility of communicating with the dreamer also opens up prospects for identifying physiological markers of consciousness and dreaming and decoding the activity of our brain during the dream experience, in order to better understand the role of dreaming and sleep. .
[1] It is a rare (1 in 3 to 5,000 people) and non-curable chronic disease, which most often occurs between the ages of 10 and 30. This sleep disorder is characterized by nighttime sleep of normal duration but of poor quality, excessive daytime sleepiness and uncontrollable drowsiness that can occur at any time of the day, even during full activity.
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