Lucid Dreaming — Nightmares are bad for your health and how to control them.

When Dr Michelle Carr was a postdoctoral researcher at Swansea University, she would cycle down a long, dark stretch of the Welsh coastline every morning in a race to beat the sunrise. Waiting for her at 7.30am sharp, in a stout little building nestled in Swansea Bay, was a revolving cast of volunteers, whose dreams Dr Carr was preparing to manipulate.
She would watch from the control room as they slept with electrodes attached to their heads, for the signs that they had entered REM sleep, the brief window where vivid dreaming is most likely to occur.
“Play the cue!” Dr Carr whispered excitedly the first time she spotted a participant’s eyes moving around under their eyelids. Another researcher hit a button, playing a set of three beeps into the test subject’s room. Then they watched as the random eye movements transformed into intentional glances left and right.
One of the women was sound asleep but aware that she was dreaming and was speaking back to the researchers from inside her dream – an example of what’s known as “lucid dreaming”, and a crucial part of Dr Carr’s field of study. “It’s really cool to see those worlds collide within the lab,” she says. “You have no idea what they’re dreaming about, but you also know that they’re aware of the fact that they’re in the sleep lab, that they’re in this experiment, and they’re communicating directly to you.”