Corticomuscular Coherence Analysis for Robotic Assisted Reaching Task

This study investigated the sensitivity of cortico-muscular coherence (CMC) as a tool for analyzing neuromuscular communication, addressing the need for more precise diagnostic methods for neurological conditions. CMC, derived from EEG and EMG signals, reflects functional connectivity between the motor cortex and target muscles. The analysis utilized the open-access NeBULA database, which includes high-density EEG and EMG data. The study focused on data from 20 healthy volunteers (9 men and 11 women) aged 20-50 years, who performed a button-reaching task under three robotic assistance conditions: "Task-Free," "Task-Low," and "Task-High". Results showed that Mu-band (8-12 Hz) CMC was significantly modulated by the task, unlike the Beta (15-30 Hz) and Gamma (30-50 Hz) bands. Mean CMC values were consistently higher in the "Task-Free" condition and decreased with the introduction of robotic assistance. Furthermore, a group analysis revealed significant differences in Mu-band CMC between males and females for specific electrode pairs, such as C3-Anterior Deltoid and Cz-Anterior Deltoid, during assisted tasks. In these cases, males exhibited significantly higher mean CMC values than females. In conclusion, this study demonstrates that Mu-band CMC is a sensitive functional biomarker for neuromotor pathways. Its modulation by task demands and its ability to differentiate neural activation profiles between sexes support its use as a robust technique for investigating neuromotor biomarkers and developing more objective, personalized diagnostic and therapeutic tools.