Kentaro Ono
Groove-the pleasurable urge to move in response to rhythmic music-is known to engage motor planning networks in the brain, and β band oscillations over motor cortex correlate with groove strength during passive listening. Whether this groove-related β modulation extends to active sensorimotor synchronization, and whether it tracks behavioral synchronization performance, remains an open question. Here we tested whether groove ratings are associated with motor cortical β suppression and tapping stability during active synchronization and after auditory input ceases. Twenty-eight healthy adults tapped with the right index finger in time with drum rhythm patterns that varied in syncopation level (low, medium, high) while electroencephalography (EEG) was recorded. Following the tapping task, participants rated the groove strength of each pattern. β power over left central electrodes contralateral to the tapping hand was estimated separately for the synchronization phase, in which participants tapped to the rhythm without an explicit beat cue, and the continuation phase, in which tapping was maintained in silence. Groove ratings showed an inverted U-shaped relationship with syncopation level, peaking at intermediate syncopation. Tapping variability and β suppression over motor cortex showed the complementary pattern, both reaching their minimum at the same intermediate syncopation level. Rhythm patterns that were subsequently rated as more groove-inducing were associated with lower β power during both the synchronization and continuation phases, indicating that patterns rated as more groove-inducing were associated with stronger motor cortical suppression regardless of phase. These results indicate that groove is associated with greater motor cortical engagement during active sensorimotor synchronization, and that this engagement persists beyond the presence of auditory input, linking the subjective urge to move with more stable rhythmic motor control.