SHORT LATENCY SOMATOSENSORY POTENTIALS IN HUMANS

A sequence of high frequency potentials was averaged from the scalp of 10 normal human subjects during the first 25 msec following median nerve stimulation. There was a large positive component with a peak latency between 18.9 and 22.3 msec localized to the somatosensory area contralateral to stimulation. This was preceded by an early positive potential arising peripherally (peak latency 7.7-9.7) and at least 3 negative to positive deflections which appear to originate in multiple subcortical structures. When corrected for arm length, intersubject variability was less than 5% for all components. With further clarification, this method should allow one to study neural conduction along the entire somatosensory pathway. © 1979.