[Generators of somatosensory evoked potentials following stimulation of nerves of the arm].

The cervical evoked potentials recorded above the 7th spinous process represent activity from the dorsal roots (N 11a) and the dorsal horn (N 13a), respectively. The upper neck responses are attributed to ascending activity in the dorsal column (N 11b) and the activation of the cuneate nucleus (N 13b). Scalp-leads from the contralateral sensory hand area using an Fz-reference consistently exhibit a sequence of components with successively more rostrally located generator sites: P 15 in or near the thalamus, N 20/P 25 in the primary sensory cortex and the following components in the parietal association fields (area 5 and 7).