A medium is a person who allegedly communicates with dead people or spirits. Many times the spirits also materialize while the medium is communicating with them. Also, tapping sounds can sometimes be heard during these communications along with levitation or movement of objects. James and his colleagues also investigated some fraudulent mediums. One particular medium who was investigated for eighteen years by James and his colleagues in the ASPR and who was found to have the true gift of Mediumship was Leonora Piper, a Boston housewife.
Usually mediums go into a trance state, which is different than the hearing of voices and other personalities that sometimes are a part of mental illness. A Successful medium learns to control his or her trance states. Mrs. Piper stated: "To her the trance was entirely otherworldly. She said it began 'as if something were passing over my brain making it numb; a sensation similar to what I experienced when I was etherized, only the unpleasant odor of ether is absent...When she woke, her hands and arms tingled. She could see the occupants of the room again, but only at a distance." (Blum, 2006, p. 181)
A report was completed in 1894 by some of the founding members of the ASPR who worked with James. This report entitled "Census of Hallucinations" was presented at the International Congress of Experimental Psychology, which convened in Paris for the first time on August 6-10, 1889. This conference was held to teach "what psychologists generally would describe as casual hallucinations of sane persons" (Blum (2006), p. 393). England, France, Germany Russia and Brazil also participated giving reports. The British census of 17,000 surveyed was the largest and the American study of 7, 123 surveyed was second. "All concluded that death-day apparitions occurred in startling numbers. In other words, they stated that a ghost appearing after the person dies is a proven fact." (Blum (2006), pp. 182-183)
It is interesting that in 1889 there was apparently a distinction between "hallucinations of sane persons" and those of insane persons; whereas, it is widely perceived among psychology colleagues and peers at the present time that hallucinations are generally labels as psychotic experiences and are viewed negatively.