Sleep paralysis: a terrifying encounter with our own mind

Sleep paralysis can sometimes make us feel like we're floating outside our body. The out-of-body experience can reliably be reproduced in the laboratory by disrupting the temporo-parietal junction in the brain. This region helps build a body image based on inputs it receives from the senses. The area is usually turned off during REM sleep.

In sleep paralysis, there is no feedback from the body telling the brain how to build the body image, resulting in out-of-body hallucinations such as seeing your body float in the air or sink deep into the bed.

The most distressing during sleep paralysis is seeing an intruder that sometimes attacks the sleeper. Anything the imagination can invent can happen. Commonly, the intruder chokes the person by crushing his chest. The creature can include details like a demonic face with sharp teeth and cat eyes.

One explanation is that in the same way that people who are born with a missing arm may experience phantom limbs - they feel the missing limb - a person can 'feel' another phantom person during sleep paralysis.

Research suggests that your beliefs about sleep paralysis can shape your experience.

In Denmark, people see sleep paralysis as something trivial caused by the brain. Egyptians fear dying from sleep paralysis and consequently have longer episodes. The fear will activate fear areas in the brain, making them more likely to wake up during REM. The escalating anxiety would worsen sleep paralysis, causing more intense bodily hallucinations.

• Understanding what is happening during sleep paralysis helps to prevent fear cycles. People are relieved to hear they are not "crazy".
• Literally turn your back on the terrifying monster by dreaming a coherent dream in which you are aware you are dreaming.
• Meditation relaxation (MR) therapy was designed to treat sleep paralysis. The treatment includes techniques of cognitive reappraisals, emotional distancing, meditation, and muscle relaxation.