title: Seeing your error alters my pointing: observing systematic pointing errors induces sensori-motor after-effects.
abstract: During the procedure of prism adaptation, subjects execute pointing movements to visual targets under a lateral optical displacement: as consequence of the discrepancy between visual and proprioceptive inputs, their visuo-motor activity is characterized by pointing errors. The perception of such final errors triggers error-correction processes that eventually result into sensori-motor compensation, opposite to the prismatic displacement (i.e., after-effects). Here we tested whether the mere observation of erroneous pointing movements, similar to those executed during prism adaptation, is sufficient to produce adaptation-like after-effects. Neurotypical participants observed, from a first-person perspective, the examiner's arm making incorrect pointing movements that systematically overshot visual targets location to the right, thus simulating a rightward optical deviation. Three classical after-effect measures (proprioceptive, visual and visual-proprioceptive shift) were recorded before and after first-person's perspective observation of pointing errors. Results showed that mere visual exposure to an arm that systematically points on the right-side of a target (i.e., without error correction) produces a leftward after-effect, which mostly affects the observer's proprioceptive estimation of her body midline. In addition, being exposed to such a constant visual error induced in the observer the illusion "to feel" the seen movement. These findings indicate that it is possible to elicit sensori-motor after-effects by mere observation of movement errors.
authors: INSERM U1028, Lyon Neuroscience Research Center, ImpAct Team, CNRS UMR5292, Lyon, France. r.ronchi@auxologico.it
authors: Roberta
authors: R
authors: Ronchi
authors: Patrice
authors: P
authors: Revol
authors: Masahiro
authors: M
authors: Katayama
authors: Yves
authors: Y
authors: Rossetti
authors: Alessandro
authors: A
authors: Farnè
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D005366:Figural Aftereffect / Q000502:physiology*; D006801:Humans; D007088:Illusions / Q000502:physiology*; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D009068:Movement / Q000502:physiology; D010775:Photic Stimulation; D011434:Proprioception / Q000502:physiology; D011984:Sensory Receptor Cells / Q000502:physiology*; D011795:Surveys and Questionnaires; D055815:Young Adult