A Developmental Study of AEP N2 and Autonomic versus Controlled Processes in Normal Children

In the developomental investigations on event related potentials (ERPs) , it is not well known whether the N2 elicited by startle stimuli changes at the same rate as the developmental P3b changes, or shows some different developmental course. The present research provided the data on the developmental and maturational changes of AEP (auditory evoked potential) N2 component elicited by the acoustic sudden stimuli. The results showed that the AEP N2 appeared to develop at different rates in the developmental curves of latencies and amplitudes, as compared with the P3a elicited by sudden stimuli and the P3b elicited by an oddball paradigm. The peak latency of electromyographic(EMG) responses in young children was longer than in adults, and decreased progressively as a function of age, reaching adult values by late adolescence or the early twenties. These findings suggest that the N2 elicited by sudden stimuli has a different develpomnetal time table in children, and may reflect a bottom-up activity of the sensory processing taking place in the brainstem, as compared with the P3b component.