Ontogenesis of human brainstem evoked potential amplitude

Brainstem evoked potentials (BEP's) were studied in human subjects ranging in age from birth to adulthood. The BEP's were recorded from the surface of the scalp referenced to either ear while brief clicks were delivered binaurally through earphones. Separate analyses of variance were computed for the peak-to-peak amplitude of each component of the BEP. Significant age effects were observed documenting the strong relationship between human brainstem development and amplitude changes in the BEP. The independent maturation of these structures was reflected by the significant interaction between age and peaks. Despite small fluctuations in the maturational curve of each peak, strong linear and quadratic trends were apparent. The research presented here provides evidence of significant amplitude changes in the BEP accompanying human development. These findings indicate that brainstem maturation is not yet complete at birth and that the components believed to represent spatially separate generators in the auditory system show distinct maturational stages.