title: Can you tickle yourself if you swap bodies with someone else?
abstract: The effect of the body transfer illusion on the perceived strength of self- and externally-generated "tickle" sensations was investigated. As expected, externally generated movement produced significantly higher ratings of tickliness than those associated with self-generated movements. Surprisingly, the body transfer illusion had no influence on the ratings of tickliness, suggesting that highly surprising, and therefore hard to predict, experiences of body image and first-person perspective do not abolish the attenuation of tickle sensations. In addition, evidence was found that a version of the rubber hand illusion exists within the body transfer illusion. We situate our findings within the larger debate over sensory attenuation: (1) there is an attenuation of prediction errors that depends upon the context in which sensory input is predicted (i.e., efference copy), and (2) sensory attenuation is a necessary consequence of self-generated movement irrespective of context (i.e., active inference). The results support the notion of active inference.
authors.affiliation: School of Applied Media and Social Sciences, Monash University, Northways Road, Churchill, Victoria 3842, Australia. Electronic address: george.vandoorn@monash.edu.
authors.forename: George
authors.initials: G
authors.lastname: Van Doorn
authors.affiliation: Department of Philosophy, Monash University, Clayton Road, Clayton, Victoria 3800, Australia. Electronic address: jakob.hohwy@monash.edu.
authors.forename: Jakob
authors.initials: J
authors.lastname: Hohwy
authors.affiliation: School of Applied Media and Social Sciences, Monash University, Northways Road, Churchill, Victoria 3842, Australia. Electronic address: mark.symmons@monash.edu.
authors.forename: Mark
authors.initials: M
authors.lastname: Symmons
mesh_terms: D000328:Adult; D001828:Body Image / Q000523:psychology*; D005260:Female; D006225:Hand; D006801:Humans; D007088:Illusions / Q000502:physiology / Q000523:psychology*; D008297:Male; D009068:Movement / Q000502:physiology*; D010812:Physical Stimulation / Q000379:methods*; D011795:Surveys and Questionnaires; D014110:Touch / Q000502:physiology*
keywords: Active inference; Body transfer illusion; Self- and externally generated movement; Tickle