"Sleep Paralysis (SP) condition in which someone, most often lying in a supine position, about to drop off to sleep, or just upon waking from sleep realizes that s/he is unable to move, or speak, or cry out. This may last a few seconds or several moments, occasionally longer." (http://watarts.uwaterloo.ca/~acheyne/S_P2.html)
A sensation of not being able to move, even in the slightest manner, your muscles. Sometimes a twitch is accomplished. Sometimes I lie for several minutes trapped inside my own body and completely aware of it. Whether this is a fully concious or semi-concious state is something I'm struggling with defining - I'm concious in the sense that I can look out through my eyes and perceive color, recognize my surroundings, and focus my attention, but it feels like I'm caught halfway between The Dreaming and The Wakening.
"People frequently report feeling a "presence" that is often described as malevolent, threatening, or evil. An intense sense of dread and terror is very common. The presence is likely to be vaguely felt or sensed just out of sight but thought to be watching or monitoring, often with intense interest, sometimes standing by, or sitting on, the bed. On some occasions the presence may attack, strangling and exerting crushing pressure on the chest. People also report auditory, visual, proprioceptive, and tactile hallucinations, as well as floating sensations and out-of-body experiences (Hufford, 1982). These various sensory experiences have been referred to collectively as hypnagogic and hypnopompic experiences (HHEs). People frequently try, unsuccessfully, to cry out. After seconds or minutes one feels suddenly released from the paralysis, but may be left with a lingering anxiety. Extreme effort to move may even produce phantom movements in which there is proprioceptive feedback of movement that conflicts with visual disconfirmation of any movement of the limb. People may also report severe pain in the limbs when trying to move them."
(http://watarts.uwaterloo.ca/~acheyne/S_P2.html)
