Simultaneous Recordings of Scalp and Epidural Somatosensory-Evoked Responses in Man

Science  11 Sep 1964:
Vol. 145, Issue 3637, pp. 1199-1200
DOI: 10.1126/science.145.3637.1199


The calvarium and scalp markedly attenuate the amplitude, but do not alter the latency or frequency, of somatosensory responses evoked by electrical stimulation of the contralateral median nerve in man. With scalp electrodes no significant potentials are obtained that are not also present in the epidural recordings when proper averaging techniques are used. The somatosensory-evoked response recorded with scalp electrodes in man appears to be the result of brain activity.