title: Visual illusion of tool use recalibrates tactile perception.
abstract: Brief use of a tool recalibrates multisensory representations of the user's body, a phenomenon called tool embodiment. Despite two decades of research, little is known about its boundary conditions. It has been widely argued that embodiment requires active tool use, suggesting a critical role for somatosensory and motor feedback. The present study used a visual illusion to cast doubt on this view. We used a mirror-based setup to induce a visual experience of tool use with an arm that was in fact stationary. Following illusory tool use, tactile perception was recalibrated on this stationary arm, and with equal magnitude as physical use. Recalibration was not found following illusory passive tool holding, and could not be accounted for by sensory conflict or general interhemispheric plasticity. These results suggest visual tool-use signals play a critical role in driving tool embodiment.
authors.affiliation: Department of Cognitive Science, University of California, San Diego, United States; Kavli Institute for Brain and Mind, University of California, San Diego, United States. Electronic address: luke.miller@inserm.fr.
authors.forename: Luke E
authors.initials: LE
authors.lastname: Miller
authors.affiliation: Department of Psychological Sciences, Birkbeck, University of London, United Kingdom.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Longo
authors.affiliation: Department of Cognitive Science, University of California, San Diego, United States; Neurosciences Graduate Program, University of California, San Diego, United States; Kavli Institute for Brain and Mind, University of California, San Diego, United States.
authors.forename: Ayse P
authors.initials: AP
authors.lastname: Saygin
mesh_terms: D000328:Adult; D001828:Body Image; D003220:Conflict, Psychological; D005260:Female; D006801:Humans; D007088:Illusions; D008297:Male; D011434:Proprioception; D011597:Psychomotor Performance; D053001:Tool Use Behavior; D055698:Touch Perception; D055815:Young Adult
keywords: Body representation; Embodiment; Multisensory; Plasticity; Psychophysics; Somatosensory