The Effects of Different in Nontarget Stimulus Intensity on Auditory Event-related Potential P300 / 听力学及言语疾病杂志

ABSTRACT

Objective To compare the latency and amplitude of normal subject's auditory event -related po‐tentials(AERP) via P300 evoked by same target stimulation and different intensitve non target stimulation ,and to explore the appropriate intensity of target and nontarget stimulus which evoke typical P300 at the same frequency . Methods A total of 20 normal young volunteers were induced in this study .Each subject received 3 AERP tests , respectively by the same tone burst target stimulus(60 dB nHL ,1 kHz) and different intensity levels for the non target stimulus(50 ,65 ,70 dB nHL ,and 1 kHz) ,and the latency and amplitude of 3 group's P300 were compared . Results In all cases ,P300 was successfully induced .The latencies of 3 group's P300 were 316 .25 ± 21 .16 ms , 320 .83 ± 22 .64 ms ,318 .44 ± 25 .82 ms (P>0 .05) ,respectively and the amplitudes of 3 group's P300 were 5 .02 ± 2 .04 μV ,7 .42 ± 2 .58 μV ,3 .54 ± 2 .23 μV (P<0 .01) ,respectively .The amplitude of the moderate intensity group was greater than the high intensity group and low intensity group ,and the amplitude differences were not statistical‐ly significant between the high and the low intensity groups .Conclusion Different intensity levels of nontarget stim‐ulus do not affect the latency of P300 ,but significantly affect the amplitude .Along with the decreasing of the inten‐sity difference of target and nontarget stimula ,the P300 amplitude raise gradually .A typical P300 is induced at the same frequency when the target stimuli and non target stimuli are 60 dB nHL and 65 dB nHL respectively .