On the threshold between wakefulness and sleep, some people suffer from a fascinating - and alarming - phenomenon known as Exploding Head Syndrome (EHS).
The sleep disorder, although harmless, is extremely annoying: it is characterized by the auditory perception of loud noises or explosions, even when we are about to fall asleep.
The intensity of these sounds is such that it immediately awakens the sufferer.
"It was a very loud sound inside my head, from the top of my skull," Dave Lovos, a musician and guitar maker, tells National Geographic. His "scare" was accompanied by a brief vision of a car crash, just as he was transitioning to sleep.
This episode is not isolated, and reflects the complexity of SCE as a parasomnia, a categorization that also covers phenomena such as somnambulism, sleep paralysis, and leg spasms known as "myoclonic spasms".
SCE occurs in an ephemeral state of transition from wakefulness to sleep, known as the "hypnagogic state", and is thought to be a kind of neuronal short-circuit. The noises reported are varied: from shocks and gunshots to slamming doors, the sounds reflect a broad spectrum of intense auditory experiences.
Discovered and initially named in 1876 by Silas Weir Mitchell and later renamed by J.M.S. Pearce in the 1980s, SCE has been the subject of scientific interest, although studies are, to date, scarce. Research indicates that both men and women are equally affected.
Interestingly, an article published in 2018 suggests that the philosopher René Descartes may have experienced SCE in the 17th century, an experience that he himself considered to be decisive in his philosophical journey.
"My office would be a lot messier if there really were heads exploding," says Brian Sharpless, a certified clinical psychologist specializing in sleep. "As long as you don't have pain during [an episode], you have nothing to worry about," he stresses.
