A review of generators of the brainstem auditory evoked potential: contribution of an experimental study

The goal of this paper is to briefly review the evidence for the generator(s) of each wave of the brainstem auditory evoked potential. An experimental study is included that adds data relevant to the question of generators. Thus, the distributions of amplitude and latency are plotted throughout the scalp for each of the positive and negative waves (16) of this potential (20 normal ears). For amplitudes, seven are maximal on the midline with five on Cz (IN, IV, V, VN, and VIN) and two on FZ (I' and IIIN); two are on the ipsilateral side (II and VIIN), and seven are maximal on the contralateral side (I, IIN, III, VI, VII, VIII, and VIIIN). For latency to peak, none is earliest on the midline; only five are on the ipsilateral side (I', III, IIIN, IV, and VIIN), and all the rest are on the contralateral side. The falloff from the maximal amplitude is rectilinearly related to the square of the distance from the peak, but this relationship is not the "inverse square law." These data are then discussed with reference to the possible generators of each wave.