Distinct Neural Signatures Underlie Finger Tapping and Walking to Auditory Rhythms

Neural oscillations synchronize with rhythmic stimuli, shaping perception and action. Auditory-motor synchronization (AMS) enhances this process but most evidence comes from finger tapping, an attentionally demanding voluntary behaviour. Whether motor-driven modulation of neural synchronization generalizes to more automatic movements like walking remains unclear. In this study, we used mobile EEG to compare neural synchronization to auditory rhythms during tapping and walking in 40 older male and female participants, manipulating cognitive load (single vs. dual task) and task instructions (synchronize with vs. ignore metronome). EEG components attuned to metronome frequencies were extracted and complementary measures of neural synchronization were computed (phase coupling to the stimulus, power at the stimulus frequency, and the stability of instantaneous frequencies). Both movements enhanced neural synchronization relative to passive listening. Neural synchronization was further increased by instructions to synchronize, but only during tapping. This instruction-facilitating effect was lost in dual tasks. These findings suggest that AMS recruits movement-dependent neural and cognitive mechanisms, depending on where AMS lies on a continuum from voluntary-controlled to automatic forms of coordination, with implications for rhythm-based interventions in aging. Significance statementNeural coupling to stimuli in the environment shape perception and action, but its dependence on movement type and cognitive control is poorly understood. Using mobile EEG, we show that both finger tapping and walking enhance neural coupling to the auditory stimuli, but tapping is uniquely modulated by task factors. Our findings suggest that cortical involvement during rhythmic motor tasks differs for voluntary (tapping) and automatic (walking) behaviours. As gait can move from being mostly automatic to voluntary-controlled (e.g., under heightened cognitive load, in motor disorders), it offers a unique opportunity to study the dynamic interactions between sensory, motor, and cognitive processes supporting neural coupling to auditory stimuli.