We might otherwise dismiss Greeley's experiences as merely odd examples of anomalistic psychology, his brain playing perceptural tricks, a neurological malfunctioning, if it weren't for some other provocative evidence of unexpected effects in his outward life.

For one thing, Greeley's experiences began to infect, much like a contagion, other people close to him. His 34-year-old son, Scott, and Scott's girlfriend, both saw similar images and entities on some of the nights they stayed at Greeley's house. These visitations periodically continued even when Scott and his intimate partner were away in other cities. (In the diagnostic manual of the American Psychiatric Association, this type of contagion is explained away as a "shared psychotic disorder.")

Equally puzzling, Greeley and the people around him began to notice strange marks and wounds appearing on his body in the aftermath of the more intense visitations. For the first time in his life he had spontaneous nose bleeds while reading a book or eating a meal. He would awaken to find one eye severely bloodshot, or a finger swollen as if smashed by a sledgehammer, yet he retained no memory of having been injured.

Try as I might, my intuition does not facilitate me fully embracing a traditional psychiatric perspective explaining away all of these phenomena, though I do feel these images and experiences are primarily projections of the unconscious human mind. As evidenced by research into stigmata, our beliefs and unconscious desires can even produce wounds and other physical effects. But the triggers for these events, a partial reason why some of us are more susceptible, may exist independent of our brains.

While hypnopompic and hypnogogic sleep are the likely explanations for such experiences, Phenomena Magazine went on to cite electromagnetic fields as another source. That strikes me as rather ridiculous. Ghost hunters use untested electromagnetic field detectors to detect the presence of ghosts. Citing electromagnetic fields as a cause for such sightings strikes me as pseudoscience. The magazine also claimed that aliens could come here from other dimensions, via wormhole bridge - patently ridiculous.

It's likely that normal but misunderstood sleep patterns as well as sleep disorders are behind alien abduction stories and ghost sightings. Too many encounters have too much in common with sleep patterns and disorders.