Lucid Dreaming Was Proven in a Lab With a Flick of the Eyes

Shortly after eight on the morning of April 12, 1975, a pen on a polygraph in a university sleep lab in Hull, England, swung hard to one side, then the other, then back again. The man wired to the machine was fast asleep. He was also, by prior arrangement, sending a message.

That zigzag of ink marks the moment lucid dreaming stopped being a story people told at breakfast and became something a laboratory could record. It took one researcher, one unusually gifted dreamer, and a loophole in the sleeping body's own security system.

The trouble with dreams as evidence

A lucid dream is a dream in which the dreamer knows it is a dream while it is still going on. The term comes from the Dutch psychiatrist Frederik van Eeden, who used it in 1913 and meant lucid in the sense of insight, not vividness.

Reports of the experience are far older than the name. Evidence was the problem. For most of the twentieth century, as the psychologist Susan Blackmore has recounted, orthodox sleep researchers held that lucid dreams could not be real dreams at all. The accepted explanation was that people were waking briefly in the night and misremembering the episode as sleep.

It was a hard position to dislodge, because every dream report arrives after the fact. To show that a person could be conscious and asleep at once, someone would have to get testimony out of the dream while it was still happening.

During rapid eye movement sleep, the stage in which the most vivid dreams occur, the body's voluntary muscles go slack. That seems to rule out any signal from the inside: a dreamer cannot wave, speak or press a button.

The exception is in the stage's name. The eyes keep moving.

Keith Hearne, a psychology researcher at the University of Hull, saw what that meant. If a dreamer who knew he was dreaming deliberately looked left and right inside the dream, his physical eyes ought to follow, and the electrodes taped beside them would write the movement onto the chart. In his own later account, ocular signaling simply went around the paralysis of REM sleep.

His subject was Alan Worsley, a practiced lucid dreamer. The two agreed on a signal in advance, and on that April morning Worsley delivered it: a run of about eight sweeping left and right movements, unmistakably deliberate, in the middle of an otherwise ordinary REM period. Hearne has said he stayed silent so as not to wake him. "It was like getting signals from another world," he later recalled.