Recent studies have proposed that the mental rotation of body parts can be accomplished by calling upon visual and somatomotor resources which, at a functional level, would correspond to different routes toward a single solution [1]. In this study, we investigated the effect of somato-motor and visual strategies upon the mental simulation of a task that involved postural adjustments. Subjects were asked to stand up on a vertical force platform and instructed either to 1) rest during 20 s (ST), 2) count mentally from 1 to 15 (CO), 3) imagine themselves executing a bilateral plantar flexion 15 times (IM), and 4) execute the same movement 15 times (EX). They were further classified as visual or somato-motor dominant, according to the strategy reported as adopted to perform IM. Mental chronometry showed that mean time spent in IM matched that of EX, differing from CO for both groups. Index of stabilometric modulation during IM was computed by reference to CO. Higher index values for area and amplitude of displacement in the antero posterior (y) axis were found for the somato-motor as compared to the visual group. The stabilometric departure found for visual and somato-motor dominant subjects suggests that each imagery mode activates a distinct subset of cortical and subcortical brain networks.
Stabilometry; Motor imagery; Balance
