Improvements in proprioceptive functioning influence multisensory-motor integration in 7- to 13-year-old children.

Accurate and efficient sensorimotor behavior depends on precise localization of the body in space, which may be estimated using multiple sensory modalities (i.e., vision and proprioception). Although age-related differences in multisensory-motor integration across childhood have been previously reported, the extent to which age-related changes in unimodal functioning affect multisensory-motor integration is unclear. The purpose of the current study was to address this knowledge gap. Thirty-seven 7- to 13-year-old children moved their dominant hand in a target localization task to visual, proprioceptive, and concurrent visual and proprioceptive stimuli. During a subsequent experimental phase, we introduced a perturbation that placed the concurrent visual and proprioceptive stimuli in conflicting locations (incongruent condition) to determine the relative contributions of vision and proprioception to the multisensory estimate of target position. Results revealed age-related differences in the localization of incongruent stimuli in which the visual estimate of target position contributed more to the multisensory estimate in the younger children whereas the proprioceptive estimate was up-weighted in the older children. Moreover, above and beyond the effects of age, differences in proprioceptive functioning systematically influenced the relative contributions of vision and proprioception to the multisensory estimate during the incongruent trials. Specifically, improvements in proprioceptive functioning resulted in an up-weighting of proprioception, suggesting that the central nervous system of school-aged children utilizes information about unimodal functioning to integrate redundant sensorimotor inputs.