Scientists Offer Explanation for Alien Abductions New York Times TOKYO -- About once a week, Jean-Christophe Terrillon wakes up and senses the presence of a threatening, evil being beside his bed. Terror ripples through him, and he tries to move or call out.
But he is paralyzed, unable to raise an arm or make a sound. His ears ring, a weight presses down on his chest, and he has to struggle for breath.
"I feel an intense pressure in my head, as if it's going to explode," said Mr. Terrillon, a Canadian physicist doing research in Japan. Sometimes he finds himself transported upward and looking down on his body, or else sent hurtling through a long tunnel, and these episodes are terrifying even for a scientist like him who does not believe that evil spirits go around haunting people.
Called sleep paralysis, this disorder -- the result of a disconnect between brain and body as a person is on the fringe of sleep -- is turning out to be increasingly common, affecting nearly half of all people at least once. Moreover, a growing number of scholars believe that sleep paralysis may help explain many ancient reports of attacks by witches and modern claims of abduction by space aliens.
"I think it can explain claims of witchcraft and alien abduction," said Kazuhiko Fukuda, a psychologist at Fukushima University in Japan and a leading expert on sleep paralysis. Research in Japan has had a headstart because sleep paralysis is well-known to most Japanese, who call it kanashibari, while it is little-known and less studied in the West.
"We have a framework for it, but in North America there's no concept for people to understand what has happened to them," Professor Fukuda said. "So if Americans have the experience and if they have heard of alien abductions, then they may think, 'Aha, it's alien abduction!' "
Sleep paralysis was once thought to be very rare. But recent studies in Canada, Japan, China and the United States have suggested that it may strike at least 40 percent or 50 percent of all people at least once, and a study in Newfoundland, Canada, found that more than 60 percent had experienced it.
There, as in Japan, people have a name for the condition and some scholars believe that people are therefore more likely to identify it when it happens to them. In Newfoundland, it is called "old hag" because it is associated with visions of an old witch sitting on the chest of a paralyzed sleeper, sometimes throttling the neck with her hands.
Sleep paralysis seems to have been described since ancient times, and an episode appears in "Moby Dick" and perhaps also in the 18th century Henry Fuseli painting, "The Nightmare," which shows a goblin sitting on the stomach of a sleeping woman. What is striking is that although the symptoms of sleep paralysis are generally very similar, the images in the hallucinations and the interpretation of them seem to vary.
Europeans seem to have interpreted ancient sleep paralysis as assaults or abductions by witches taking them off for a forcible ride on a broomstick. Chinese called it "gui ya," or ghost pressure, and believed that a ghost sat on and assaulted sleepers.
In the West Indies, sleep paralysis was called "kokma" and meant a ghost baby who jumped on the sleeper's chest and attacked the throat. In old Japan, it sometimes seems to have been interpreted as a giant devil whose foot came down on the sleeper's chest.
"People will draw on the most plausible account in their repertoire to explain their experience," said Al Cheyne, an associate professor of psychology at the University of Waterloo in Canada. "Trolls or witches no longer constitute plausible interpretations of these hallucinations. The notion of aliens from outer space is more contemporary and somewhat more plausible to the modern mind. So a flight on a broomstick is replaced by a teleportation to a waiting spaceship."
Dr. Cheyne said that in a survey he had worked on involving more than 2,000 people identified as experiencing sleep paralysis, hundreds described experiences similar to alien abduction.
"A sensed presence, vague gibberish spoken in one's ear, shadowy creatures moving about the room, a strange immobility, a crushing pressure and painful sensations in various parts of the body -- these are compatible not just with an assault by a primitive demon but also with probing by alien experimenters," Dr. Cheyne said. "And the sensations of floating and flying account for the reports of levitation and transport to alien vessels."
In recent years there has been a huge increase in the number of people who insist that they have been kidnapped by alien creatures from outer space, perhaps subjected to medical experiments and then released again. These claims have been a bit of a scientific puzzle, because they strike most people as utterly wacky and yet they are relatively widespread. One well-publicized (and widely criticized) Roper Poll published in 1992 suggested that nearly four million American reported experiences akin to alien abduction.
Surprisingly, one study found that these people were no more fantasy-prone than the general population and had slightly higher intelligence. Many shun publicity and show signs of feeling traumatized and humiliated.
Several scholars have found that people are more likely to report alien abductions when they have been exposed to movies or books about the idea. Simon Sherwood, a researcher on sleep paralysis in England, said that in one case study he gathered, a regular sufferer of sleep paralysis watched an alien film and then had a hallucination of "little blue aliens" inserting a metal probe into his forehead.
The growing professional literature on sleep paralysis has often mentioned the parallels with reports of alien abductions. Still, many scholars are reluctant to research the connection for fear of tainting their reputations. Others say that a connection is plausible but unproved.
Tomoka Takeuchi, a Japanese expert on sleep paralysis who is now conducting research at Brock University in Ontario, Canada, said that a connection might eventually be demonstrated scientifically but added: "I hesitate to speculate too much."
Those who believe in alien abductions deny that sleep paralysis could be behind it all. John E. Mack, a Harvard University Medical School professor who is the most prominent defender of the possibility of abductions, argues that sleep paralysis simply does not fit the evidence. He notes that at least a few abduction reports come from remote places where people are not exposed to movies or tales of U.F.O.'s, and that many happen in daylight and involve people who seem to have been awake and alert.
Other defenders of abduction theories say aliens may be clever enough to use sleep paralysis in their kidnappings.
Sleep paralysis researchers say that as many as 60 percent of intense abduction experiences were linked to sleep, and some of the reported symptoms -- noises, smells, paralysis, levitation, terror, images of frightening intruders -- are very similar to those of sleep paralysis.
Still, sleep paralysis cannot be a full explanation because ome reports of alien abduction do not involve sleep. Leonard S. Newman, a psychologist at the University of Illinois at Chicago who has studied alien abductions, argues that they are false memories -- in some cases triggered by sleep paralysis but at other times by day dreams or fantasies.
"People, especially when they are hypnotized, can easily weave together images, dreams, fantasies and things that they might just have heard or read about into elaborate pseudo-memories that they are confident are real," Professor Newman said in an E-mail interview.
So what is sleep paralysis?
Even after many years of study, particularly in the last decade, it remains mysterious. Experts have trouble even saying definitively whether a person is asleep or awake during sleep paralysis.
"In the classic definition, you are awake," said Emmanuel Mignot, director of the Center for Narcolepsy at Stanford University Medical School. "But in practice, there's a gradient between being awake and being in REM sleep," he said, adding that sleep paralysis lies in a murky place on that slope.
During REM sleep -- the period when rapid eye movement takes place -- the body essentially turns itself off and disconnects from the brain. This is a safety measure, so that people do not physically act out their dreams, and it means that people are effectively paralyzed during part of their sleep. Even automatic reflexes, like kicking when the knee is tapped, do not work during REM sleep.
Sleep paralysis seems to occur when the body is in REM sleep and so is paralyzed and disconnected from the brain, while the brain has emerged from sleep and is either awake or semiawake. Usually after a minute or two the spell is broken and the person is able to move again, as the brain and body re-establish their connection.
Just what is going on in the brain during sleep paralysis is unclear.
The person experiencing the paralysis certainly feels completely awake and "sees" the room clearly, but laboratory experiments in Japan show that sometimes people experiencing sleep paralysis do not even open their eyes.
Sleep paralysis sometimes runs in families and appears to have a genetic component. Although it is normally harmless, some scholars believe it may be linked to a pattern of unexplained deaths among Hmong and other groups in Southeast Asia. The victims are usually healthy young people who die in their sleep, sometimes after fighting for breath but without thrashing around, and their faces show grimaces of terror.
Among ordinary people, sleep paralysis occurs most often after jet lag or periods of sleeplessness that interrupt normal REM patterns. Men and women seem to suffer it at equal rates, and although it is most common in the teen-age years, it is reported at all ages.
Aside from witchcraft and alien abduction, sleep paralysis is also sometimes mentioned as a possible link to shamanism and to dream interpretation and even to near-death experiences. But for many sufferers, the growing research in the field is reassuring simply because it demonstrates that they are not alone in their terrifying night-time paralysis and hallucinations.
"Sometimes I'm just glad that I didn't live a long time ago," said Mr. Terrillon, the Canadian physicist in Japan. "Because maybe people who had this in the olden days were put in madhouses."
By Nicholas D. Kristof
July 6, 1999