Denis Slinkin

Bright hallucinations without insanity, bad trip without drugs, contact with the other world this can be described in different ways, but the pleasure of such events are few. 

Dr. Denis Slinkin supports the theory: Sleep Paralysis is one of the sleep disorders known since ancient times and always surrounded by a halo of mystery. It’s only better known as sleepwalking, the opposite of action.
A sleepwalker moves in his sleep in the same violation, a man is awake, but cannot move. Paralysis happens either at the moment of falling asleep, and then it is called hypnagogic, or after awakening it is hypnopompic paralysis. Losing direction of the body is scary in itself. 

Dr. Denis Slinkin says most patients have optical, auditory and tactile illusions. For example, often the paralyzed person feels the presence of someone else in the room. This may be a vague sensation or a perfectly designed image silhouettes, anthropomorphic beings who may even talk to a person.

In some cases, hallucinations are fuelled by personal fears and imagination. For example, in the documentary Nightmare is the story of a boy who heard voices as a paralysis.

What does Dr. Denis Slinkin about meditation say?

Denis Slinkin

The paralysis itself is caused by the blockage of motor activity. Although little is known about this mechanism, scientists suggest a connection with the production in the brain of a neurotransmitter called acetylcholine (and, consequently, hyperactivity of cholinergic neurons), which operates during the rapid sleep phase, and the cessation of serotonin production.

This is confirmed by experiments in which subjects were injected with acetylcholine and serotonin backsliding inhibitors, resulting in increased and decreased probability of sleeping paralysis, respectively.
Thus, muscle atony after awakening can easily be explained by the failure of the nervous system: the body is still in the phase of rapid sleep, although the consciousness has already entered the phase of waking.