Citation

Ronchi R, Revol P, Katayama M, Rossetti Y, Farnè A. PLoS One 2011; 6(6): e21070.

Affiliation

INSERM U1028, Lyon Neuroscience Research Center, ImpAct Team, CNRS UMR5292, Lyon, France.

Copyright

(Copyright © 2011, Public Library of Science)

DOI

10.1371/journal.pone.0021070

PMID

21731649

PMCID

PMC3121736

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.

Language: en