[Neurorehabilitative intervention with neurofeedback system using functional near-infrared spectroscopy]

Recent advance in Brain-Machine interface (BMI) technology, including analysis of brain signal, enable a real-time interaction between patients and environment bypassing their damaged neuromuscular systems. Although most of researches have focused on substituting output function, it has been growing interest in applying this technology for restoring their brain. Several studies have proved that feedback of cortical activities (neurofeedback) enable regulating brain activation voluntarily. According to this notion, we have developed a real-time neurofeedback system mediated by near-infrared spectroscopy (NIRS) as a neurofeedback tool in neurorehabilitation. First, we have evaluated whether real-time cortical oxygenated hemoglobin (OxyHb) feedback signals correlated with reference OxyHb signals analyzed off-line during a motor execution task. Our results showed high correlation between results from two analyses. Second, we investigated whether the self-assessment scores for kinesthetic motor imagery and motor imagery related cortical activation was enhanced by neurofeedback. Our experiment with right handed healthy subjects revealed significant improvement of the imagery scale, and enhanced cortical activations including the contralateral premotor area. These results suggest that the neurofeedback technique may improve the efficacy of mental practice with motor imagery.