ABSTRACT
Objective To investigate the normal waveform,lantency and amplitude of auditory event-related potentials (ERPs) of exogenous components in children at different ages,and summarize the developmental rules and clinical perspectives of exogenous ERPs according to the International Federation of Clinical Neurophysiology (IFCN) Recommended Standards in 2009.Methods One hundred and thirty-six children aged from 3 to 17 years old (admitted in the departments from healthcare,orthopedics,general surgery,and respiratory and digestive diseases,and those recovered from respiratory infection and gastrointestinal infection),and healthy adults (from undergraduates of Chongqing medical university) were recruited in this study from 2008 to 2010.They were divided into 4 groups in accordance with their ages,that is,3 ～5,＞ 5 ～7,＞ 7 ～9,and ＞ 9 ～17 years old groups,and adult group (22 ～29 years old).ERPs were recorded from the midline site (Cz) with classical auditory Oddball paradigm.Each subject was tested twice or more to determine waveform repeatability.The overlapped graphs of ERPs under target and standard stimuli were obtained in the potentiometer.The exogenous ERPs,including P1,N1,P2 and N2,lantency and amplitude were measured.Results The latencies of exogenous ERPs under target and standard stimuli were shortened in a non-uniform manner with the increasing of age.No matter under target or standard stimuli,over 95％ of mean latencies of exogenous ERPs were within the range of 2SD.In addition to N1 component,the amplitude of P1,P2 and N2 components induced by target stimulus were in a trend of increased first and then decreased with the increasing of age.Compared with the children,the amplitude was much lower in the adults and adolescents (P ＜ 0.05).The N2 component induced by target stimulus was absent among 95％ healthy adults.The Standard deviations of amplitudes of exogenous components were great in all aged groups,indicating significant individual differences.Conclusion The latencies of exogenous ERPs are shortened with the increasing of age.Target stimulus will produce more stable results than the standard stimulus,and the ERPs under target stimulus can reflect the primary auditory cortex function of temporal lobe,and are independent on patients' cooperation.