Real-time dialogue between experimenters and dreamers during REM sleep
Authors: Jarrod Gott
Kristoffer Appel
Anastasia Mangiaruga
Emma Chabani
Delphine Oudiette
Isabelle Arnulf
Gordon Pipa
Sarah Witkowski
Jean-Baptiste Maranci
Bruce Caughran
Martin Dresler
Karen R Konkoly
Remington Mallett
Jonathan B Berent
Ken A Paller
Smaranda Leu-Semenescu
Frederik D Weber
Başak Türker
Christopher Y Mazurek
Nathan W Whitmore
Journal: Current Biology (2021)
Discipline: BIOLOGY & BIOCHEMISTRY
Keywords: REM sleep; consciousness; dreams; interactive dreaming; lucid dream
Affiliations: Department of Psychology and Cognitive Neuroscience Program, Northwestern University, Evanston, IL, USA., Institute of Cognitive Science, Osnabrück University, Osnabrück, Germany; Institute of Sleep and Dream Technologies, Hamburg, Germany., Institut du Cerveau - Paris Brain Institute - ICM, Sorbonne Université, Inserm, CNRS, Paris, France., Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands; Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy., Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands., Department of Psychology, University of Texas at Austin, Austin, TX, USA., NextSense, Inc., Mountain View, CA, USA., Institut du Cerveau - Paris Brain Institute - ICM, Sorbonne Université, Inserm, CNRS, Paris, France; AP-HP, Pitié-Salpêtrière Hospital, Sleep Disorders Department, Paris, France., Institute of Cognitive Science, Osnabrück University, Osnabrück, Germany., Department of Psychology and Cognitive Neuroscience Program, Northwestern University, Evanston, IL, USA. Electronic address: .

Abstract:  Dreams take us to a different reality, a hallucinatory world that feels as real as any waking experience. These often-bizarre episodes are emblematic of human sleep but have yet to be adequately explained. Retrospective dream reports are subject to distortion and forgetting, presenting a fundamental challenge for neuroscientific studies of dreaming. Here we show that individuals who are asleep and in the midst of a lucid dream (aware of the fact that they are currently dreaming) can perceive questions from an experimenter and provide answers using electrophysiological signals. We implemented our procedures for two-way communication during polysomnographically verified rapid-eye-movement (REM) sleep in 36 individuals. Some had minimal prior experience with lucid dreaming, others were frequent lucid dreamers, and one was a patient with narcolepsy who had frequent lucid dreams. During REM sleep, these individuals exhibited various capabilities, including performing veridical perceptual analysis of novel information, maintaining information in working memory, computing simple answers, and expressing volitional replies. Their responses included distinctive eye movements and selective facial muscle contractions, constituting correctly answered questions on 29 occasions across 6 of the individuals tested. These repeated observations of interactive dreaming, documented by four independent laboratory groups, demonstrate that phenomenological and cognitive characteristics of dreaming can be interrogated in real time. This relatively unexplored communication channel can enable a variety of practical applications and a new strategy for the empirical exploration of dreams. 

Retracted: No

PubPeer comments:
 This article was reviewed on the error bar podcast episode 4: https: theerrorbar.com ?e=4 story 22: https: theerrorbar.com ?s=22. The review was done in the light of newspaper headlines about the article. The slightly-edited transcript is copied here: headline: PEOPLE CAN ANSWER QUESTIONS WHILE ASLEEP tweet: the ability to communicate with researchers while asleep is an exciting prospect for brain science. 1 in 12 of the volunteers in this study might have been able to do it. sometimes. a bit. description: Scientific American, The Independent, and The Dail Mail all reported on a remarkable study of the apparent two-way communication between researchers and volunteers who were asleep. the volunteers were experiencing lucid dreams where they have some control over their dreams. in the study - which was actually four independent studies from four countries, all with slightly different methods and participants - 36 volunteers were trained to give simple eye-movements or facial twitches in response to (very) simple maths questions. three left-right eye movements is the correct answer to one plus two ; five eyebrow twitches is the wrong answer to two plus two . the volunteers then went to sleep in the laboratory, connected to some electrodes recording activity from their brain and facial muscles. the remarkable bit of the story is that when the volunteers started showing signs of the rapid eye movement sleep phase which indicates dreaming, the volunteers were then asked the maths questions again. and some of them responded - sometimes - with eye movements or facial twitches. and for a not-insignificant proportion of those questions, the movements corresponded with the correct answer. the journalists concluded that two-way communication is possible during sleep, that we can break into peoples dreams and leave them messages. while the numbers of successful communications remained quite small, the scientists hailed this a proof-of-concept study. evaluation: remarkable claims require remarkable evidence. this is a remarkable report, so the error bar is raising its evidence threshold to remarkable . i want to believe it. it should be possible to communicate with lucid dreamers. it fits with my expectations. but i m not convinced. i don t necessarily believe that the evidence is not there in the data. i just don t think the reported analyses show this evidence sufficiently - or correctly first, the overall study is actually four independent studies from four groups that have been somewhat cobbled together post-hoc. multi-site studies can be fantastically powerful ways to do prospective science, but this seems to be a retrospective collaboration. was the evidence from the individual groups insufficient? perhaps this paper is the pilot study for a prospective collaboration? second, each study tests a different population, recruited in a different way, using different methods. the experimental training, task, interventions analysis are all different, yet the data are all pooled. and third, that s my main problem with the paper. all the data are pooled together as if they are equivalent. but they re not. the data come from different numbers of people different numbers of sleeping dreaming events. for example, 80% of the data come from just 27% of the participants. but the statistics all ignore this hierarchical or clustered structure in the data. 22 participants in the US were trained to dream lucidly; 10 Germans were recruited from an (expert) lucid dreamers forum; 37 Dutch volunteers had had at least one lucid dream; there was a single French narcolepsy patient. these 70 participants were reduced in various slightly opaque ways to the 36 mentioned in the report. from these 36 dreamers, only 6 produced one or more correct responses to questions asked during sleep. statistically, then, should we be analysing either the 36 tested participants, or the 6 selected responder participants? we re then asked to focus on 158 communication attempts, themselves selected from a total of 850. (there were also 802 control attempts.) and from these 158 selected attempts, only 29 resulted in a correct answer. some of these 29 events were presented graphically in the paper. much of the analysis was done by independent experts eyes, blind to condition - which is great. but why was there no attempt to analyse the data computationally? surely such signals - if they exist in the data - can be detected automatically? finally, the statistical approach here is a mess: sometimes the stats use the participant as the unit of analysis - an important concept about what is being measured - sometimes it s the experimental session being analysed, sometimes it s the data epoch, sometimes it s the individual responses. what you want to be able to say at the end of a study like this is that people can answer questions when they re asleep . but we can t say that. what we can say is that some questions can be answered when people are asleep - the unit of analysis is the questions, not the people. in summary, there is so much whittling selection of data here that it is very hard to tell what s wheat and what s chaff. conclusion: a highly-selective analysis of highly selected participants shows that a small minority of them seem able to respond to simple questions while they sleep. the stats here are a mess. ,