Citation

Mercier C, Aballea A, Vargas CD, Paillard J, Sirigu A. Cereb. Cortex 2008; 18(2): 272-277.

Affiliation

Centre de Neuroscience Cognitive CNRS, 67 Blvd. Pinel, 69675 Bron, France.

Copyright

(Copyright © 2008, Oxford University Press)

DOI

10.1093/cercor/bhm052

PMID

17517681

Abstract

Several studies have shown a cortico-spinal facilitation during motor imagery. This facilitation effect is weaker when the actual hand posture is incompatible with the imagined movement. To determine whether the source of this interference effect arises from online proprioceptive information, we examined transcranial magnetic stimulation (TMS)-induced motor-evoked potentials during motor imagery in the deafferented subject G.L. The patient and 7 control subjects were asked to close their eyes and imagine joining the tips of the thumb and the little finger while maintaining a hand posture compatible or incompatible with the imagined movement. Contrary to control subjects' performance, G.L.'s results show that the facilitation observed during motor imagery was independent of the hand posture. To examine how vision of the hand interacts with the imagery process, G.L. and control subjects performed the same task with the eyes open. Like control subjects, when G.L. looked at her hand, a greater facilitation was observed when her hand posture was compatible with the imagined movement than when it was incompatible. These results suggest that in the absence of proprioception, vision may facilitate or inhibit motor representations and support the idea that limb position in the brain is organized around multisensory representations.

Language: en