Have you ever found yourself paralyzed as you drift off to sleep or as you are waking up? During these moments of paralysis, did you experience strange things?
Perhaps you experienced flashes of lightning or heard loud noises, like explosions similar to a firework, as you were drifting off or waking up?
These situations describe the sensations of sleep paralysis and exploding head syndrome, respectively.
Despite their scary-sounding names, these conditions are not dangerous and are normally benign, although they can be disturbing for individuals.
Surprisingly, little is known about the conditions. In an effort to learn more a group of academics from around the world are teaming up to conduct a survey asking people to detail their sleep experiences and to describe their experience of sleep paralysis or exploding head syndrome, should they experience them.
Prof. Alice Gregory from Goldsmith's, University of London, is an academic who specializes in the development and co-occurrence of sleep problems, anxiety and depression throughout the life course. Together with the BBC's Focus Magazine, she and colleagues are running a survey asking people about their experiences as they drift off to, and wake up from, sleep.
The findings from the survey will help inform researchers about the conditions and shape how treatment or advice for the conditions is developed and applied.
To take part in the survey click here