Credit: F. Scott Schafer/ Corbis
As a university STUDENT in 1964, David J. Hufford met the dreaded Night Crusher. Exhausted from a bout of glandular fever and studying for finals, Hufford retreated one December day to his rented university room and fell into a deep sleep.
An hour later, he awoke with a start to the sound of the bedroom door creaking open - the same door he had locked and bolted before going to bed. Hufford then heard footsteps moving toward his bed and felt an evil presence. Terror gripped the young man, who couldn't move a muscle, his eyes plastered open in fright.
Without warning, the malevolent entity, whatever it was, jumped onto Hufford's chest. An oppressive weight compressed his rib cage. Breathing became difficult and Hufford felt a pair of hands encircle his neck and start to squeeze. "I thought I was going to die," he says.
At that point, the lock on Hufford's muscles gave way. He jerked up and sprinted several blocks to take shelter in the student union building. "It was very puzzling," he recalls with a strained chuckle, "but I told nobody about what had happened."
Hufford's perspective on his strange encounter was transformed in 1971. He was at that time a young anthropologist studying folklore in Newfoundland, Canada. Some of the region's inhabitants told him about their eerily similar night-time encounters and called the threatening entity the 'Old Hag'. Most cases unfold as follows: a person wakes up paralysed and perceives an evil presence, then a hag or witch climbs on top of the petrified victim, creating a crushing sensation on his or her chest.
It took Hufford another year to establish that what he and the others had experienced corresponds to the event, lasting seconds or minutes, that sleep researchers call sleep paralysis. Although widely acknowledged among traditional cultures, sleep paralysis is one of the most prevalent, yet least recognised, mental phenomena for people in industrialised societies, Hufford says.
Nearly 40 years after Hufford's discovery, sleep paralysis has begun to attract intensive scientific attention. Several years ago, a special issue of the journal Transcultural Psychiatry included a series of papers on the condition's widespread prevalence, regional varieties and mental health implications.
Sleep paralysis differs from nocturnal panic, in which a person awakens in terror with no memory of a dream. Neither does sleep paralysis resemble a night terror, in which a person suddenly emerges from slumber in apparent fear, flailing and shouting, but then falls back to sleep and doesn't recall the incident in the morning.
Curiously, although the word nightmare originally described sleep paralysis, it now refers to a fearful or disturbing dream, says Hufford, now at the Pennsylvania State Medical Centre in the U.S. town of Hershey.
Several hundred years ago, the English referred to night-time sensations of chest pressure from witches or other supernatural beings as the "mare", from the Anglo-Saxon 'merran', meaning to crush. The term eventually morphed into nightmare - the crusher who comes in the night.

My experience of dreams...
An interesting read. Twice in my live I experienced sleep paralysis, the first time I thought I saw a shadowy figure approach me, very afraid, tried to scream but just air. But once I broke out of it, I did not in any way think what I saw was real. I guess I had enough reasoning to understand it was just a dream state. The second time although paralyzed and hard to breath, I did not experience any shadowy figure.
What I do find interesting is how similar the experiences of people have. The feeling of some creature or entity. I think it is largely induced by the feeling of panic, not being able to move. Just like I always wondered why is it everyone I have ever met with Tourette syndrome, usually scream profanities or things that would normally be unacceptable to say in public.
When I was younger, I often experienced lucid dreaming, although is rare I do anymore. This typically happened when having a very bad dream. The level of fear seemed to eventually trigger a state of awareness that I understood I was in a dream, and either woke myself up, or sometimes 'changed' the dream, in that I would suddenly flip to a new dream and slip back into a normal dream state, or in some cases alter the current dream to something more favorable. During these lucid states, I remembered the particular dreams well.
I eventually discovered many of the traits of lucid dreaming are again very common.
The state of dreaming I always found fascinating. In some dreams, I've had completely unexpected conversations with a group of individuals on different subjects, and then upon waking, always thought to myself, how interesting, I just had a conversation with multiple constructs of my own mind, talking to myself!
Being a software developer, this lead me to the idea, that your 'mind' is much like multiple programs, each one it's own 'personality' , often specialized in a particular thought grouping. In most people, a 'primary' program, controls the rest, sometimes lending more control to a particular program/personality subset. What many refer to 'zoning' is a good example of this. Intense concentration, and elevated performance, for a short time. In schizophrenics the 'main' program/personality for what ever reason is unable to maintain control and others are allowed to take complete control for short time periods.
The programming of these personality groupings is largely by society & culture, and thus the very similar interpretations, especially to certain ideas that reflect variations in culture. (some demons, some witchs, some entities, some gremlins, some aliens and others nothing at all, these are programmed aspects of culture and belief systems)
This combined with a common 'working' of the brain, in that it has different subsystems for combining and interpreting input and test routines for analyzing what the brain considers to be reality, these subsystems tend to work the same for most people.
And thats by 25.5 cents worth of my own experiences and short theory of why people have such similar experiences.
The X-Factor
the stuff of nightmares
i would never imagined i'd be sharing this type of "experience" that lasted 6 months or more the beings first called my name then hello
i told them to go away they came into my bedroom a few days later
i felt a curious empty tho' filled with atoms sort of like an xray
was unable to move something was happening in my pubic area
i even felt a sharp object enter my vagina -
i have read of abductions - this went on intermittently
as a result i was afraid to go to sleep
the harassment and sleep deprivation
led to a breakdown and trip to emergency then to a locked ward
i cannot say if it were real or not - i live in new mexico site of the famous ufo landings in 1947 i am a reasonable elder woman who is skeptical tho' willing to listen to what seems to be impossible
i still am afraid recently as i was drifting off a feeling of dread came over me and a dark almost smokelike figure loomed out of the closet and came to suffocate or rape me i woke with a large start now i sleep with the bathroom light seems silly as a child would i am taking meds for anxiety - flite or fite vigilance that is disconcerting
in hopes of a better future rev joyce bove'e