Sidis, B. (1904). Hypnoid states or underground life. In B. Sidis & S. P. Goodhart, Multiple personality: An experimental investigation into the nature of human individuality (pp. 327-340). New York, NY, US: D Appleton & Company.
http://dx.doi.org/10.1037/10559-042
Hypnoid states consist of the presence of two or more fully independent moments consciousness, they are found in the phenomena of automatic writing, shell hearing, crystal gazing and various other psychopathic conditions. Most of the cases of functional derangement due to mental dissociation fall under the category of hypnoid states. The hypnoid state really differs but little from the hypnoidic- it is simply the hypnoidic personality working underground and showing its effects in waking life. Case studies are presented to illustrate the author's points (PsycINFO Database Record (c) 2016 APA, all rights reserved)