Scientists have identified a new phenomenon they describe as "interactive dreaming"— when people experiencing deep sleep and lucid dreams are able to follow instructions, answer simple yes-or-no questions, and even solve basic math problems.
Lucid dreams are when the dreamer is aware they're dreaming.
The finding, described in a study published last week in the journal Current Biology, adds a whole new level of understanding to what happens in our brains when we're dreaming. It could eventually teach us how to train our dreaming to help us towards a particular goal, for example, or to treat a particular mental health problem.
There's plenty about the psychology of sleep that remains a mystery, including the rapid eye movement (REM) stage where dreams usually occur. Being able to get responses from sleepers in real time, rather than relying on reports afterwards, could be useful.
"We found that individuals in REM sleep can interact with an experimenter and engage in real-time communication," Ken Paller, a psychologist from Northwestern University and co-author of the new study, said. "We also showed that dreamers are capable of comprehending questions, engaging in working-memory operations, and producing answers."
"Most people might predict that this would not be possible — that people would either wake up when asked a question or fail to answer, and certainly not comprehend a question without misconstruing it," he added.
Sleepers could correctly answer questions while lucid dreaming
The researchers worked with 36 people in experiments across four different laboratories in France, Germany, the Netherlands, and the US. One study volunteer had narcolepsy and frequently experienced lucid dreams, while the others varied in terms of their experience with lucid dreaming.
During the deepest stages of sleep, as monitored by electroencephalogram (EEG) instruments, scientists interacted with the study participants through spoken audio, flashing lights, and physical touch. The sleepers were asked to answer simple math questions, to count light flashes or physical touches, and to respond to basic yes or no questions, like "Can you speak Spanish?"
The dreamers answered using eye movements or facial-muscle movements that the researchers had told them to use in advance. In 15 of the study's 57 sleep sessions, six participants communicated to the researchers that they were lucid dreaming. During those lucid dreaming sessions, the sleepers answered questions correctly nearly 20% of the time.
Several witnesses confirmed the sleepers' responses during the study.
"We put the results together because we felt that the combination of results from four different labs using different approaches most convincingly attests to the reality of this phenomenon of two-way communication," Karen Konkoly, a co-author of the study, said.
The researchers usually woke up the sleepers after they gave a successful response in order to get the participants to report on their dreams. In some cases, the dreamers remembered the questions or lights as being overlaid on the dream; in others, the external inputs came through something inside the dream (like a car radio).
The finding could help treat sleeping disorders
The study authors said trying to communicate with lucid dreamers is typically like trying to get in touch with an astronaut in space. So it's the immediacy of the responses that make this new approach so exciting.
The research could be helpful in the future study of dreams, memory, and how important sleep is for fixing memories in place. It might also be useful in the treatment of sleeping disorders, and might even give us a way to train what we see in our dreams.
"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," the study authors wrote.
"This relatively unexplored communication channel can enable a variety of practical applications and a new strategy for the empirical exploration of dreams," they added.
SEE ALSO: Freud's interpretation of why we dream may be wrong — here's what's really going on
Join the conversation about this story »
NOW WATCH: How you can control your dreams — an expert explains how lucid dreaming works