title: Anomalous bodily-self experiences among recreational ketamine users.
abstract: BACKGROUND
  Out-of-body experiences present a unique paradigm to investigate cognitive and neural mechanisms of bodily-self processes and their disorders. Previous work on out-of-body experiences associated with sleep paralysis supported a model in which illusory movement experiences reflect disrupted bodily-self integration generating anomalous vestibular and motor sensations. Further disintegration and progression of the experience may then give rise to out-of-body feelings, which in turn may instigate out-of-body autoscopy.
  
  
  METHODS
  The current study assesses the disintegration model through analyses of out-of-body experiences reports from an online survey of individuals reporting recreational ketamine use (n=128) and cross-validation in a sample of nonketamine polydrug users (n=64). Path analyses using intensity and frequency measures of anomalous experiences assess the fit of seven competing models.
  
  
  RESULTS
  The disintegration model (illusory movement → out-of-body feelings → out-of-body autoscopy) emerged as the best fitting model overall and results support full mediation of the relation between illusory movement experiences and out-of-body autoscopy by out-of-body feelings. Moreover, lifetime measures of ketamine use predicted the frequency of illusory movement experiences.
  
  
  CONCLUSIONS
  The results corroborate this structural model of out-of-body phenomena and encourage a framework for future studies into aetiological mechanisms of out-of-body experiences to include neurochemical systems.
authors.affiliation: Department of Psychology, Ryerson University, Toronto, Ontario, Canada.
authors.forename: Leanne K
authors.initials: LK
authors.lastname: Wilkins
authors.forename: Todd A
authors.initials: TA
authors.lastname: Girard
authors.forename: J Allan
authors.initials: JA
authors.lastname: Cheyne
mesh_terms: D000293:Adolescent; D000328:Adult; D000778:Anesthetics, Dissociative / Q000008:administration & dosage; D001828:Body Image / Q000523:psychology; D003861:Depersonalization / Q000139:chemically induced* / Q000523:psychology*; D005260:Female; D006801:Humans; D013287:Illicit Drugs; D007088:Illusions / Q000187:drug effects* / Q000523:psychology*; D007649:Ketamine / Q000008:administration & dosage*; D008297:Male; D008960:Models, Psychological; D019966:Substance-Related Disorders / Q000523:psychology; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D000778:Anesthetics, Dissociative; D013287:Illicit Drugs; D007649:Ketamine