Instead of waiting for dreamers to tell us about a dream after it has ended, when they have transitioned to the waking state, we sought to obtain evidence showing that it is possible to interview them about their dreams at the time they are experiencing them. 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. Demonstrating the viability of this “interactive dreaming”—when experimenter and dreamer communicate with each other in real time—would be a large step forward to promote future progress in dream research.

Here, we report multiple demonstrations of successful two-way communication during lucid dreams achieved by four independent scientific teams in France, Germany, the Netherlands, and the USA. We substantiate the validity of this interactive-dreaming phenomenon by bringing together results obtained using a diverse set of strategies. Several methods for communicating into and out of dreams were used, as shown in Figure 1. Lucid dreamers were able to follow instructions to compute mathematical operations, answer yes-or-no questions, or discriminate stimuli in the visual, tactile, and auditory modalities. They were able to respond using volitional control of gaze direction or of different facial muscles. There were three different participant categories: (1) experienced lucid dreamers, (2) healthy people with minimal prior experience who we trained to lucid dream, and (3) a patient with narcolepsy, a neurological disorder characterized by excessive daytime sleepiness, short-latency REM sleep periods, and frequent lucid dreaming. Evidence of two-way communication was found with all three participant categories, and also with both nocturnal sleep and daytime naps.

https://www.cell.com/current-biology/fulltext/S0960-9822(21)00059-2