Sleep Paralysis / Hypnopompic Hallucination.
documentedabduction_entityAbduction Research
Peer-reviewed REM/wake-desync mechanism reproducing core abduction features (paralysis, chest pressure, sensed presence, figures by the bed).
Sleep paralysis is a normal REM/wake desynchrony in which the mind wakes while the body stays paralyzed; ~25% of people experience it at least once and ~5% get the full sensory show. Hypnopompic hallucinations on waking produce a sensed presence, chest pressure, floating, lights and figures - the exact abduction template - with cultural expectation supplying the 'alien' interpretation. McNally and Clancy documented this in abduction claimants. It is a competing-documented scientific explanation, not a claim.