TOPOGRAPHY OF SPATIALLY ENHANCED HUMAN SHORT-LATENCY SOMATOSENSORY-EVOKED POTENTIALS

IN the present study modern high resolution electroencephalography (EE G) was used to spatially enhance human median nerve short-latency soma tosensory evoked potentials (SEPs). It was shown that the spatially en hanced N30 consisted of two frontal subcomponents, one located in the frontal-lateral area of the scalp, the other located in the frontal-me sial area. Both of these subcomponents were most reduced in amplitude (or disappeared) during concomitant hand movement ipsilateral to the s timulus, but were differentially influenced by executed contralateral movement and imagined ipsilateral movement. These results support the hypothesis of an involvement of the frontal-mesial cortex (including t he supplementary motor area) in the generation of the frontal N30.