Sleep paralysis can be a terrifying experience for the near 50 percent of people who have had an episode. It's the middle of the night, your eyes are open, dark shapes are gathering around you, something has grabbed your feet, and you can't move. You can't even scream.

A new article by British researchers calls for more attention to be paid in the medical community to sleep paralysis, also known as "night terrors."

"Sleep paralysis is a period of transient, consciously experienced paralysis either when going to sleep or waking up," wrote the researchers from the Anomalistic Psychology Research Unit at Goldsmiths, University of London. "During an episode the individual is fully conscious, able to open their eyes but aware that it is not possible to move limbs, head or trunk." The person might have trouble breathing and, "the individual might experience hallucinations."

Scientists are aware that the phenomenon is related to stress and involves a disconnect between the brain and the body during the dreaming, or REM, portion of sleep.

"Putting it simply, wakefulness has occurred, but the body and part of the brain is still in REM sleep," the researchers wrote in the journal The Psychologist. "Most urgently, there is a need for greater awareness of the nature of the sleep paralysis amongst the general public and, particularly, amongst health professionals in order to minimize the anxiety and distress that often results from such attacks."

This article was provided by Inside Science News Service, which is supported by the American Institute of Physics, a not-for-profit publisher of scientific journals.