The Nightmare

Before you read on, be warned. Sleep paralysis may be an infectious concept. One participant in this documentary says it never happened to him until after his girlfriend told him about her experiences, and there's evidence to suggest he may be onto something. If you're the sort of person who would watch Sadako's video from Ring or speak the name of the Candyman five times into a mirror, by all means read on - otherwise, well, you have been warned.

Documentary this may be, but it's very much in horror movie territory, and filmed as such. Of the eight people telling their stories, most speak from the shadows or are surrounded by the paraphernalia of sleep - something they have learned to fear. Sleep paralysis, which affects around a third of UK adults at some point in their lives, can be a terrifying experience, especially for those who don't understand it and think they must by dying or suffering from strokes. Despite its frequency, it's rarely talked about - perhaps something that stops it spreading, certainly something that makes it harder for many of those affected to cope with.

The scientific explanation for sleep paralysis is that when we sleep our bodies produce a chemical that immobilises our muscles, keeping us from acting out what we dream. This is a process that fails to work properly in sleepwalkers, and at the other end of the scale it can persist into the early stages of wakefulness, creating a sensation of panic as sleepers start to come round by find they can't move. As this is also the stage at which dreams are most intense, the panic can manifest as a nightmare or sufferers can experience hallucinations; time perception can be distorted so that it feels as if this goes on for ages, even though it's unlikely to last more than a couple of minutes. It's not only frightening, however - in some cases it's associated with breathing problems (sleep apnoea) which can present a real health risk, yet many of those affected never think of seeing a doctor about it.

There's a lot of interesting material to explore here, but The Nightmare goes beyond the factual to look at the impact of the condition on individual lives and to explore how different people have interpreted what has happened to them. Not all of the eight buy the scientific explanation. There's talk of alien abduction, of mysterious creatures making contact from a parallel dimension, of discovering Jesus by calling out to him for help in fending off what seem like demons. All those contributing share a roughly similar cultural background but the film takes a brief look at how the phenomenon is understood around the world, showing how culture influences perceptions but also highlighting striking similarities in reported experiences. Tall, shadowy figures with glowing red eyes, and smaller, cat-like creatures (such as that depicted in Fuseli's famous painting) seem to be everywhere. Are these elements of a shared primeval consciousness, the haunters of the Jungian dark, or are they something else?

One curious element here is that there's very little talk of how the experience effects people's willingness to sleep, with only one man talking about how he'd try to hold out until he was exhausted in order to try and avoid or minimise the problem. Most seems to be trying to go on with their lives as normal, despite the fact that some suffer nightly. A significant proportion of people grow out of sleep paralysis in their mid twenties, but only one person here says it's firmly in the past. Others describe how it has changed over time, sometimes 'working around' systems they put in place to try and manage it.

Alongside the personal struggles recounted here is that wider shift of perspective that every documentary maker longs to achieve. Many people who see this film will, in the process, be learning about the phenomenon for the first time, and will be startled by the landscape Ascher presents: hundreds of thousands of their fellow citizens, people they see and interact with every day, living with a secret fear, or with the memory of it. There is no cure. Doctors, like parents and lovers, often fail to take it seriously. Psychologists have developed some technique that help to reduce it in some people, but they're unreliable and are barely discussed here - this isn't a manual but an invitation to enter the world of the afflicted. Just make sure, if you're only visiting, that you're not followed when you leave.