Eye signals: proving lucidity in the lab

During REM sleep the body is largely paralysed, but the eyes still move. Around 1980, Keith Hearne in the UK and Stephen LaBerge at Stanford independently asked lucid dreamers to make a pre-agreed pattern of eye movements when they became lucid. The signals appeared on recordings while all other measures showed REM sleep, demonstrating that lucid dreams occur during sleep rather than brief awakenings.

Two-way communication

In 2021, four laboratories in the United States, France, Germany and the Netherlands reported (Konkoly et al., Current Biology) that they could pose simple questions, such as arithmetic problems, to lucid dreamers using sounds, flashes or touch, and receive correct answers through eye movements, in a number of trials. The success rate was modest, but it opened the door to real-time experiments inside dreams.

What happens in the brain

Studies suggest increased activity in frontal and parietal regions during lucidity, areas normally quieter in REM sleep and associated with self-reflection. One study reported increased frontal gamma activity during lucid dreaming (Voss et al., 2009). Samples are small, and findings vary.

What lucidity says about awareness

Lucid dreaming separates two things we usually take together: having experiences and knowing that one is having them. That makes it valuable for higher-order theories, which link consciousness to the mind’s representation of its own states.

We cover the research. For sleep problems, nightmares or sleep disorders, please consult a health professional.