[The relationship between strength and the amplitude of evoked response components in the human somatosensory cortex]

The intensity curves were determined for the individual components of the human somatosensory evoked response, led off from the contra and ipsilateral motor and contralateral visual areas. The amplitude of the early components steeply increased, reached "saturation" and decreased with more intensive stimuli, their peak latencies being constant. The late components were characterised by continuous increase of amplitude, and the decrease of peak latencies for the lowest part of the curve. The responses in both frontal regions were identical, while those from the frontal and posterior leads were significantly different. The obtained data indicate a marked difference between mechanisms producing individual components of the evoked response.