Centrifugal Effects of Voluntary Movements on Somatosensory and Auditory Evoked Potentials: An Exploratory Study

Centrifugal mechanisms play a crucial role in supporting sensorimotor integration by modulating sensory processing. Voluntary movements regulate neural activity via centrifugal effects, whereby motor commands from motor areas influence sensory areas. Previous studies have shown that the long-latency somatosensory evoked potentials (SEPs), P100 and N140, increased during stimulus-triggered movement tasks, whereby long-latency auditory evoked potentials (AEPs), N100, were suppressed by self-generated sounds. However, findings were inconsistent regarding stimulus and movement timing. Therefore, the present study was conducted to investigate whether the centrifugal effects differ between somatosensory and auditory modalities. SEPs and AEPs were recorded during movement (button-pressing), attention (stimulus counting), and passive conditions. Difference waveforms were calculated for each modality by subtracting the event-related potentials (ERPs) elicited during attention condition from the ERPs elicited during movement condition. P100, N140, and N1 amplitudes significantly increased during movement compared with attention and/or passive conditions (p < 0.05). Positive components of the difference waveforms were significantly larger in the somatosensory modality than in the auditory modality (p < 0.05). These findings suggest that movement-related modulation may be more pronounced in the SEPs than for AEPs, indicating possible modality-specific differences by centrifugal modulation. However, given the limited electrode coverage, future studies employing high-density EEG will be necessary to clarify whether centrifugal modulation differs across sensory modality.