title: Neural systems underlying observation of humanly impossible movements: an FMRI study.
abstract: Previous studies have indicated that largely overlapping parts of a complex, mainly fronto-parietal, neural network are activated during both observation and execution of an action. If these two processes are inextricably linked, increases of neural activity contingent upon action observation should be found only for movements that can actually be performed. Using functional magnetic resonance imaging, we investigated whether observation of possible and biomechanically impossible movements of fingers activated the same neural systems. Thirteen healthy subjects were scanned during observation of video-clips showing abduction/adduction movements of the right index or the little finger, which were defined as biomechanically possible or impossible according to the range of their angular displacement at the metacarpo-phalangeal joint. The mere observation of possible and impossible hand movements induced a selective activation of left precentral and left inferior frontal regions, thus indicating that motor-related areas map body actions even when they violate the constraints of human anatomy. An increase of the blood oxygen level-dependent signal selectively linked to observation of impossible hand movements was found in sensorimotor parietal regions. Our results suggest that while premotor areas code human actions regardless of whether they are biologically possible or impossible, sensorimotor parietal regions may be important for coding the plausibility of actions.
authors.affiliation: Department of Clinical Sciences and Bio-imaging, University of Chieti G. D'Annunzio, Chieti, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Costantini
authors.forename: Gaspare
authors.initials: G
authors.lastname: Galati
authors.forename: Antonio
authors.initials: A
authors.lastname: Ferretti
authors.forename: Massimo
authors.initials: M
authors.lastname: Caulo
authors.forename: Armando
authors.initials: A
authors.lastname: Tartaro
authors.forename: Gian Luca
authors.initials: GL
authors.lastname: Romani
authors.forename: Salvatore Maria
authors.initials: SM
authors.lastname: Aglioti
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods; D002540:Cerebral Cortex / Q000502:physiology*; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D005385:Fingers / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009068:Movement / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology*