In this study, we compared traditional mirror-box mirror therapy (MT) with a novel prism-reversal MT to assess their effects on EEG Mu-rhythm power and inter-electrode coherence. Ten healthy, right-handed adults (aged 20 – 29) completed three sessions under each of three conditions: no device, mirror-box, and prism goggles. EEG was recorded at 500 Hz in a shielded room, and Mu-band (8–13 Hz) power at C3/C4 was computed as the mean squared amplitude difference between baseline and a hand-movement task. A three-factor ANOVA (stimulus type×device use×session) revealed no significant main effects or interactions on group-level Mu-power. Individual ANOVAs indicated that only a minority of participants showed significant Mu-power modulation. Coherence was calculated for Alpha (8–13 Hz), low-Beta (13–20 Hz), and high-Beta (20–30 Hz) bands, and task-induced changes were analyzed via three-factor ANOVA. Significant three-way interactions emerged in all bands. In the Alpha band, enhanced posterior-parietal and centro-parietal coherence likely reflects increased visuospatial and attentional demands under prism reversal. In the high-Beta band, right-hemisphere frontal-parietal coherence changes suggest device-dependent modulation of motor-attention networks. Although no clear Mu-power effects were detected over brief sessions in healthy subjects, the observed frequency- and region-specific coherence alterations indicate that prism-reversal MT differentially engages sensorimotor and attentional circuits. Longer-term studies are warranted to determine whether these acute network changes translate into durable motor-recovery benefits.
MATSUOKA et al. (Wed,) studied this question.