title: Heightened motor and sensory (mirror-touch) referral induced by nerve block or topical anesthetic.
abstract: Mirror neurons allow us to covertly simulate the sensation and movement of others. If mirror neurons are sensory and motor neurons, why do we not actually feel this simulation- like "mirror-touch synesthetes"? Might afferent sensation normally inhibit mirror representations from reaching consciousness? We and others have reported heightened sensory referral to phantom limbs and temporarily anesthetized arms. These patients, however, had experienced illness or injury of the deafferented limb. In the current study we observe heightened sensory and motor referral to the face after unilateral nerve block for routine dental procedures. We also obtain double-blind, quantitative evidence of heightened sensory referral in healthy participants completing a mirror-touch confusion task after topical anesthetic cream is applied. We suggest that sensory and motor feedback exist in dynamic equilibrium with mirror representations; as feedback is reduced, the brain draws more upon visual information to determine- perhaps in a Bayesian manner- what to feel.
authors.affiliation: Center for Brain and Cognition, University of California, San Diego, La Jolla, CA 92093-0109, USA. lkcase@ucsd.edu
authors.forename: Laura K
authors.initials: LK
authors.lastname: Case
authors.forename: Radhika
authors.initials: R
authors.lastname: Gosavi
authors.forename: Vilayanur S
authors.initials: VS
authors.lastname: Ramachandran
mesh_terms: D000287:Administration, Topical; D000328:Adult; D000368:Aged; D000779:Anesthetics, Local / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008012:Lidocaine / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D059167:Mirror Neurons / Q000502:physiology*; D009407:Nerve Block; D010468:Perceptual Disorders / Q000209:etiology; D010591:Phantom Limb / Q000150:complications; D012677:Sensation / Q000187:drug effects / Q000502:physiology*; D000080311:Synesthesia; D014110:Touch / Q000502:physiology*; D055698:Touch Perception / Q000187:drug effects; D014796:Visual Perception / Q000187:drug effects / Q000502:physiology*; D055815:Young Adult
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine
keywords: Anesthetic; Mirror neurons; Mirror-touch synesthesia; Motor referral; Sensory referral; Simulation