Reference: Konkoly, K., Appel, K., Chabani, E., Mangiaruga, A., Gott, J., & Mallett, R. et al. (2021). Real-time dialogue between experimenters and dreamers during REM sleep. Current Biology, 31(7), 1417-1427.e6.
Guest post by Hisham Ahmed
Have you ever thought about breaking into someone’s brain and communicating with them while they are asleep? This may sound like science fiction, but it would also be an interesting way to learn more about what’s happening while we dream.
Dreaming is a very obscure phenomenon that researchers have investigated widely throughout the years. Researchers have tried to answer questions, such as: Why do we dream? How are dreams created? How is dreaming beneficial for the brain? A challenge for dream research is that we can’t know what happened during a dream. Whenever you ask people after waking, their answers may be ambiguous and lack a lot of details, or they might not remember anything at all. It’s easy to think that our brains “shut down” during rest, but sleep researchers know that this is not true.
Consider a study conducted in 2014, which demonstrated that sleepers could process spoken words and categorize them. While awake, participants were trained to press a button with their right hand if they heard an animal name and to press another button with their left hand if they heard an object name. Researchers recorded electrical activity in the brain during participants’ responses. Then, participants were allowed to sleep, and researchers played a new set of object and animal words. Electrical activity in the brain was similar during sleep as it was when participants were awake, suggesting that participants were able to categorize the words correctly during sleep1.
Lucid dreams offer a look into the sleeping mind
Lucid dreaming is a phenomenon in which a dreamer is aware of the fact that he is dreaming and he may also gain some control over the dream content. A study estimated that at least 55% of people have experienced a lucid dream once in their lifetime2. In 2021, Karen R. Konkoly and her colleagues in 4 different labs across the world (i.e., USA, France, Netherlands, and Germany) established the term “Interactive dreaming”. While sleepers were in the middle of a lucid dream, the researchers asked questions and received correct answers to these questions through eye movement or facial muscle contractions.
What did they do?
To understand the study, let’s look closer at their design. 36 participants were included in the study, and they could be divided into: (1) experienced lucid dreamers, (2) healthy people trained to lucid dream, and (3) patients with narcolepsy – a neurological disorder characterized by frequent lucid dreaming. The researchers tried to make contact with participants once they noticed – via the brain’s electrical activity recording – that participants entered REM sleep – the phase of sleep in which we are most likely to dream (and thus have lucid dreams).
Participants were instructed to indicate when they were experiencing a lucid dream by providing a signal to the researchers. For example, in the U.S. lab, participants were told to move their eyes left-to-right three times when they were lucid dreaming. Once researchers saw this signal, they began asking questions (i.e., yes/no questions and math equations). To validate this interactive dreaming phenomenon, different strategies were followed in asking questions. Questions were asked in 3 different forms: (1) through spoken words or coded in Morse code by beeping tones, (2) through Morse code using flashing light, and (3) through tactile stimulation by tapping the participant’s hand. Participants tried to answer questions using the movement of their eyes or through the contraction of their facial muscles. Once the question was answered, researchers woke the participant for a report of their experience.
What did they find?
Let’s first consider one participant’s experience in the U.S. lab. A 19-year-old participant had a 90-minute daytime nap in the lab. During the nap, he indicated he was lucid dreaming, and then researchers asked him in spoken words “8 minus 6?” Within 3 seconds, he answered correctly through moving his eyes left-to-right two times. This question was repeated, and once again the participant answered correctly via eye movements. When he awoke and researchers asked him about his dream experience, he said: “I was in a parking lot at night…then suddenly it was daytime and I was in the video game…. I thought, okay this is probably a dream. And then something weird…. I lost control of all my muscles. There was a roaring sound of blood rushing to my ears.” The experimenter asked him whether he remembered hearing any math problems, how many he answered, and what he answered. The participant reported, “I think I heard three [problems]…. I answered ‘2’ for all of them, but I don’t remember what the first one was. I just remember the last one was ‘8 minus 6’.”
Bottom of figure: methods used to transfer information between experimenters and dreamers.
Adapted from Karen R. Konkoly, 2021.
Across the four labs, there were 57 sessions where the researchers attempted to establish communication with participants during REM sleep. In only 26% of the sessions, participants successfully signalled that they were in a lucid dream. In 47% of signal-verified lucid dreaming episodes, participants correctly answered at least one question.
What do the results mean?
This study suggests that consciousness isn’t always completely shut down while we are asleep. In some cases, it’s possible to communicate with people while dreaming and learn more about the nature of their dreams. These results provide initial evidence that people can retrieve learned information and respond while they are sleeping. That is, some participants were able to use their working memory to analyze math equations. However, it is important to note that successful communication between the researchers and dreamers occurred in only a minority of the sessions. Thus, future research should attempt to replicate these findings in different populations. Nevertheless, this “interactive dreaming” phenomenon opens the door to potentially exciting applications. For example, what other kinds of communication can happen during dreams? Can people be trained to learn new skills while they sleep? Only time (and more research) will tell whether such questions are just dreams or reality.
Additional References:
1. Kouider, S., Andrillon, T., Barbosa, L., Goupil, L., & Bekinschtein, T. (2014). Inducing task-relevant responses to speech in the sleeping brain. Current Biology, 24(18), 2208-2214.
2. Saunders, D. T., Roe, C. A., Smith, G., & Clegg, H. (2016). Lucid dreaming incidence: A quality effects meta-analysis of 50 years of research. Consciousness and Cognition, 43, 197-215.
Hisham is a student at the veterinary medicine school of Cairo University. After graduation, he aspires to go to a graduate school and study neuroscience. Connect with him on Linkedin.
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