"Trance mediumship" is often seen as a form of mental mediumship. Most trance mediums remain conscious during a communication period, wherein a spirit uses the medium's mind to communicate. The spirit or spirits using the medium's mind influences the mind with the thoughts being conveyed. The medium allows the ego to step aside for the message to be delivered. At the same time, one has awareness of the thoughts coming through and may even influence the message with one's own bias. Such a trance is not to be confused with sleepwalking, as the patterns are entirely different. Castillo (1995) states,
In 1988, the magician Bob Couttie criticized the paranormal author Brian Inglis for deliberately ignoring evidence of fraud in mediumship. Couttie wrote Inglis had not familiarized himself with magician techniques.[181] In 1990 the researcher Gordon Stein discovered that the levitation photograph of the medium Carmine Mirabelli was fraudulent. The photograph was a trick as there were signs of chemical retouching under Mirabelli's feet. The retouching showed that Mirabelli was not levitating but was standing on a ladder which was erased from the photograph.[182]

In the typical deep trance, the medium may not have clear recall of all the messages conveyed while in an altered state; such people generally work with an assistant. That person selectively wrote down or otherwise recorded the medium's words. Rarely did the assistant record the responding words of the sitter and other attendants. An example of this kind of relationship can be found in the early 20th century collaboration between the trance medium Mrs. Cecil M. Cook of the William T. Stead Memorial Center in Chicago (a religious body incorporated under the statutes of the State of Illinois) and the journalist Lloyd Kenyon Jones. The latter was a non-medium Spiritualist who transcribed Cook's messages in shorthand. He edited them for publication in book and pamphlet form.[25]

In the late 1920s and early 1930s there were around one quarter of a million practising Spiritualists and some two thousand Spiritualist societies in the UK in addition to flourishing microcultures of platform mediumship and 'home circles'.[18] Spiritualism continues to be practised, primarily through various denominational Spiritualist churches in the United States, Canada, Australia and the United Kingdom. In the United Kingdom, over 340 Spiritualist churches and centres open their doors to the public and free demonstrations of mediumship are regularly performed.[19]