Beta- and gamma-band neuromagnetic oscillations in chronic stroke rehabilitation using music-supported therapy and manual training.

Neural oscillations in beta (13-30 Hz) and gamma (>30 Hz) frequency bands index a variety of sensorimotor and cognitive processes. To compare two rehabilitation regimens for chronic stroke patients with a hemiparetic hand, we randomly assigned them to either music-supported therapy or physiotherapy for 10 weeks. Previously, we reported the music group's improved motor speed, mood, well-being, and rhythm perception. Here, we investigated changes in neural oscillatory activities. Here, our magnetoencephalography (MEG) data showed significant group-by-session interaction in both somatosensory and auditory-motor paradigms. The control group exhibited a prominent increase in gamma-band frequencies accompanying the somatosensory steady-state responses entrained by 22-Hz vibrotactile stimulation, indicating compensatory functions from the contralesional brain. In contrast, the music group showed a gradual enhancement of auditory-motor coupling in beta-band event-related power changes during passive metronome listening. The music group's increase in beta dynamics in the auditory cortex aligns with our previous work and their improvement in behavioral rhythm perception. Whole-brain data during listening and tapping demonstrated reduced beta modulation in the sensorimotor and prefrontal cortices and temporal poles in the music group, likely related to movements with less effort and attention. The current findings contribute to understanding the frequency-specific communications of the auditory, sensory, and motor systems.