The terms alien abduction or abduction phenomenon describe “subjectively real memories” of being secretly kidnapped by nonhuman figures (aliens) and subjected to physical and psychological experimentation. Most scientists and mental health professionals explain these experiences by factors such as suggestibility (e.g. false memory syndrome), sleep paralysis, deception, and psychopathology. Skeptic Robert Sheaffer sees similarity between the aliens depicted in science fiction films, in particular Invaders From Mars (1953), and some of those reported to have actually abducted people. People claiming to have been abducted are usually called “abductees” or “experiencers”.
Typical claims involve forced medical examinations that emphasize the subject’s reproductive systems. Abductees sometimes claim to have been warned against environmental abuse and the dangers of nuclear weapons. The contents of the abduction narrative often seem to vary with the home culture of the alleged abductee.
Reports of the abduction phenomenon have been made around the world, but are most common in English speaking countries, especially the United States. The first alleged alien abduction claim to be widely publicized was the Betty and Barney Hill abduction in 1961.
To know more about the subject: https://en.wikipedia.org/wiki/Alien_abduction