SELECTIVE MODIFICATION OF SOMATOSENSORY-EVOKED POTENTIAL DURING VOLUNTARY FINGER MOVEMENT IN HUMANS

We examined changes in somatosensory evoked potentials (SEPs) during v oluntary movement of fingers innervated by the stimulated nerve and th ose not innervated by the stimulated nerve and the relationship to the kind of movement modality. Analysis showed that the amplitude of most components at F3', C3', and P3, except for P45 at C3, N35 and P45 al P3, decreased during voluntary finger movement tasks. Further, we foun d that the components of P40 at F3, P45 at C3', and N35 at P3 were inc reased during the voluntary pulling movement of the second and the thi rd digits compared to those during the voluntary pushing movement of t he fourth and the fifth digits, whereas all other components were decr eased at F3, C3', and P3. We also found that not all components of SEP s were decreased while some SEPs in middle latency were increased. In conclusion, we confirmed the selectivity in attenuation of the SEPs. M oreover, we noted an interesting finding that the selectivity of atten uation of the SEPs was most frequently observed in the N20, P30 (P25 a t F3), N35 (N30 at F3), and P45 (P40 at F3) components at F3, C3', and P3.