TOPOGRAPHY OF AUDITORY-EVOKED LONG-LATENCY POTENTIALS IN NORMAL-CHILDREN, WITH PARTICULAR REFERENCE TO THE N1 COMPONENT

Topographic maps of late auditory evoked potentials were obtained with the Brain Atlas III system in 34 healthy, normal hearing children age d 8-16 years. The stimulus was a 100 msec, 500 Hz tone burst, presente d separately to the left and right ears, at 75 dB HL. The resulting au ditory evoked potentials showed a prominent N1, after about 100 msec, and a topographic map with a corresponding fronto-lateral focus design ated as the focus of N1 (FN1). Foci with varying positions and amplitu des were identified in 33 of 34 subjects after left ear stimulation an d in 29 of 32 subjects after right ear stimulation. The topography sho wed a high degree of stability in most subjects, with the position of the negative ''peak'' of FN1 in front of the interaural line and with a dominance contralateral to the ear stimulated. There was a significa nt decrease in the latency of N1 with increasing age. FN1 tended to ch ange position with age and some differences from adults were also obse rved. In conclusion, a distinct topographic pattern of the N1 componen t of the late auditory evoked potentials was seen in the majority of c hildren. It remains to be established to what extent this method may b e clinically useful for disclosing functional disturbances in the cent ral auditory pathways.