Reference: Konkoly, K. R., Appel, K., Chabani, E., Mangiaruga, A., Gott, J., Mallett, R., … & Paller, K. A. (2021). Real-time dialogue between experimenters and dreamers during REM sleep. Current Biology, 31(7), 1417-1427.

Asking someone to remember their most recent dream likely results in one of two outcomes: either they launch into a long story involving their high school talent show and a lack of clothes, or they can recall very little, if anything at all.

While nearly everyone dreams, most people are notoriously bad at remembering their dreams, making experimental research on dreams difficult. However, one group of people may be uniquely suited to participate in dream research: lucid dreamers, people who have trained themselves to realize they are dreaming and to control their dreams. This dream awareness and control has opened a new avenue for dream research.

According to a meta-analysis of lucid dream studies, over half of people queried have experienced at least one lucid dream in their lifetime, with approximately 23% of people have lucid dreams at least once a month (1). There are multiple methods to trigger a lucid dream, but the mnemonic induction of lucid dreams, or MILD, procedure, first proposed by researcher Stephen LaBerge in 1980, remains a popular strategy. In this procedure, the dreamer repeatedly sets the intention to lucidly dream after spontaneously awakening from a dream. LaBerge documented his own experience using this technique in Perceptual and Motor Skills, noting that lucid dreaming is a skill that anyone can learn (2).

Despite the advances of lucid dreaming research, many studies still rely on participants to report their dreams after waking. Early research developed methods for dreamers to indicate when they had entered a lucid dream using eye movements or fist clenches (3). Using these and more complex signals, researchers have since tried to establish bidirectional communication with dreamers.  

In a 2021 paper published in Current Biology, an international team of researchers investigated different methods for interacting with dreamers (4). Research teams in France, Germany, the Netherlands, and the United States used a variety of participant groups, including expert lucid dreamers and people with narcolepsy, a neurological disorder characterized by disruptions of typical sleep-wake cycles (5). Other research teams extensively trained novice lucid dreamers before the experiment.  After participants were proficient in lucid dreaming, the teams developed signals, such as eye or facial movements, for dreamers to use to communicate with researchers.

About 26% of the participants across the four research sites successfully signaled that they were experiencing a lucid dream. Electrical brain recordings confirmed that lucid dreamers were in rapid eye movement (REM) sleep, a stage of sleep characterized by an uptick in brain activity and temporary muscle paralysis.

When participants signaled that they were in a lucid dream, researchers used flashing lights, auditory messages, or tactile stimulation to ask the dreamers simple math questions (e.g., 4 – 2 = ?) or autobiographical yes/no questions (“Do you like chocolate?”). Of the lucid dreamers, about half appropriately or correctly responded to the questions by using the pre-determined signals (two eye movements to the left indicated “2”, contracting facial muscles twice equaled “yes”).

After the participants responded to the questions, the researchers immediately woke them and asked about their dreams. Some dreamers reported that the interactions were embedded in the dreams, for example, as a question coming from an in-dream radio broadcast. Other dreamers reported that the interaction took place outside of the dream, such as a disembodied voice asking math problems. Often dreamers correctly recalled the question that had been asked but misremembered the answers.

In all, only 18% of the attempts to communicate with lucid dreamers resulted in appropriate or correct responses. However, this rate is far better than attempts to communicate with participants who were not experiencing a lucid dream: only 1 of 366 (less than 1%) of those trials resulted in an appropriate or correct response to a researcher’s question.  

Participants representing all groups in the study (expert lucid dreamers, novice lucid dreamers who underwent training, and narcoleptic patients, who frequently experience lucid dreaming) showed evidence of two-way communication. What does this mean for future research? It suggests potential applications of lucid dreaming in dream research, such as gathering real-time information about dreams or even modifying dreams as they occur.

Lucid dreaming research begins to address questions such as: What is sleep? Can parts of our brains simultaneously experience different levels of sleep, with some parts at near-awake levels while other parts are engaged in deep sleep? Are we able to use some cognitive abilities – such as working memory, which is required to solve math problems – while we are asleep? The present research doesn’t answer all of these questions, but it does represent an important step in broadening of our understanding of consciousness and cognition during sleep.

Additional References:

(1) 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.

(2) La Berge, S. P. (1980). Lucid dreaming as a learnable skill: A case study. Perceptual and Motor Skills, 51, 1039–1042.

(3) La Berge, S. P., Nagel, L. E., Dement, W. C., & Zarcone, V. P. (1981). Lucid dreaming verified by volitional communication during REM sleep. Perceptual and Motor Skills, 52(3), 727–732.

(4) Konkoly, K. R., Appel, K., Chabani, E., Mangiaruga, A., Gott, J., Mallett, R., … & Paller, K. A. (2021). Real-time dialogue between experimenters and dreamers during REM sleep. Current Biology, 31(7), 1417-1427.

(5) Narcolepsy Fact Sheet. (2020, September 30). National Institute of Neurological Disorders and Stroke.