Processing intensity at rapid rates: Evidence from auditory evoked potentials in 9-11-year-old children
Processing intensity at rapid rates: Evidence from auditory evoked potentials in 9-11-year-old children
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DOI：
10.1016/j.ijporl.2008.05.005
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发表时间：
2008-09-01
影响因子：
1.5
通讯作者：
Sussman, Elyse
中科院分区：
文献类型：
--
作者：
Dinces, Elizabeth;Sussman, Elyse
目的：理解语音的能力需要处理快速变化的声学信息。尽管强度是准确语音感知的基本线索，但人们对处理语音的快速光谱-时间特性的了解远远超过对处理强度的了解。本研究的目的是表征9-11岁典型语言发育儿童在复杂环境中快速呈现不同音调强度（即不同频率和强度）时引发的与听觉事件相关的脑电位。方法：在10 Hz的刺激频率下，分别呈现4种不同声级（66、74、78、86 dB SPL）的纯音和5种不同的刺激频率。测量听觉事件相关脑电位的潜伏期和振幅。结果：在这个快速的速度下，一个阳性成分（P1）被激发，然后是一个阴性成分。最低强度声引起的P1幅值最低，最高强度声引起的P1幅值最高。两种中间音调强度引起的P1的振幅介于最低和最高之间，但它们之间没有显著差异。P1后的负分量不受强度变化的影响。结论：在复杂环境中，快速呈现的声音强度变化仅被最早的强制性听觉分量（P1）的振幅调制，这与我们之前的研究一致，即只有P1可以跟随快速刺激速率。P1振幅变化反映的是声音之间的相对差异，而不是序列中一起呈现的声音之间响度的绝对差异。结果表明，快速声音发生的环境或背景会影响儿童P1的相对振幅。2008爱思唯尔爱尔兰有限公司版权所有。
Objective: The ability to understand speech requires processing of rapidly changing acoustic information. Much more is known about processing the rapid spectro-temporal properties of speech than is known about processing of intensity, even though intensity is a fundamental cue for accurate speech perception. The purpose for the current study was to characterize, in 9-11-year-old typically language-developing children, the auditory event-related brain potentials elicited by different tone intensities when presented in complex environments (i.e., varying in frequency and intensity) at rapid rates.Methods: Pure tones of four different intensity Levels (66, 74, 78, and 86 dB SPL) and five different stimulus frequencies were presented at a stimulus rate of 10 Hz. The latency and amplitude of the auditory event-related brain potentials were measured. Results: At this fast rate, a positive (P1) followed by a negative component was elicited. The lowest intensity sound elicited the lowest P1 amplitude and the highest intensity sound elicited the highest P1 amplitude. The P1 elicited by the two middle tone intensities had amplitudes that fell between the lowest and highest amplitudes but they were not significantly different from each other. The negative component following the P1 was unaffected by intensity variation.Conclusions: Intensity variation of sounds presented in a complex environment at a rapid rate modulated only the amplitude of the earliest obligatory auditory component (P1), consistent with our previous studies in which only the P1 could follow the rapid stimulation rate. P1 amplitude changes reflected the relative differences among the sounds, not the absolute differences in loudness among the sounds presented together in the sequence.The results suggest that the environment, or context, within which rapid sounds occur, influences the relative amplitude of the P1 in children. (C) 2008 Elsevier Ireland Ltd. All rights reserved.