Cutaneous Sensory Stimulation Intensity Modulates Beta-Band Event-Related Desynchronization and Synchronization Amplitudes.

Beta-band event-related desynchronization and synchronization elicited by somatosensory stimulation could be potential neurophysiological markers of motor function, specifically in neurological disorders; however, their characteristics in healthy individuals remain unclear. This study aimed to examine whether the amount of afferent input modulates beta-band oscillatory responses and if they are associated with motor performance in healthy adults. Magnetoencephalographic data were recorded for 24 healthy participants during cutaneous electrical stimulation of the right index finger at three intensities based on individual sensory threshold (1×, 2× and 3× thresholds). Amplitudes of beta-band event-related desynchronization and synchronization were quantified relative to a prestimulus baseline, and motor performance was assessed using the Assembly test of the Purdue Pegboard Test. Neither oscillatory response showed a significant association with motor performance. However, the proportion of participants exhibiting these responses increased with increasing stimulation intensity, indicating reduced interindividual variability at higher intensities. Amplitudes of both responses increased with higher afferent input but showed limited sensitivity to subtle differences in input amount. These results demonstrate that cutaneous stimulation can elicit beta-band oscillations in healthy individuals, reflecting afferent input and being possibly modulated by its amount. These findings contribute to improved understanding of beta-band oscillatory responses, specifically to afferent input magnitude.