Auditory Mismatch Negativity in Response to Changes of Counter-Balanced Interaural Time and Level Differences.
Auditory Mismatch Negativity in Response to Changes of Counter-Balanced Interaural Time and Level Differences.
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DOI：
10.3389/fnins.2017.00387
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发表时间：
2017
影响因子：
4.3
通讯作者：
Fukuyama H
中科院分区：
文献类型：
--
作者：
Altmann CF;Ueda R;Furukawa S;Kashino M;Mima T;Fukuyama H
耳间时间差(ITD)和耳间电平差(ILD)都是水平声源位置的信号。为了实现对我们的声学环境的统一感知，这两个线索需要整合。在本研究中，我们通过测量失配负波(MMN)来测试ITD和ILD与脑电(EEG)的这种整合。MMN可以对空间变化做出反应，至少部分产生于听觉皮质。在我们的研究中，我们的目标是测试MMN对ITD/ILD平衡线索刺激的反应。为此，我们在两种类型的区块中使用了交替声音序列的流动的奇特范式：(A)具有一致组合的ITD/ILD线索的偏侧化刺激和(B)由反平衡的、不协调的组合的ITD/ILD线索产生的中线刺激。我们观察到，对于相同的ITD/ILD线索，无论是较低的载波频率(0.5 kHz)还是较高的载波频率(4 KHz)，在改变开始后约112-128ms处都出现了显著的MMN峰值。更重要的是，我们还观察到，对于不协调组合的ITD/ILD线索，MMN的峰值出现在129ms左右，但这种影响只在较低的频率范围(0.5 kHz)下才能检测到。两种线索组合(一致/不一致)的MMN反应没有显著差异。这些结果表明，至少在较低的频率范围(0.5 kHz)，ITD和ILD在听觉皮层的MMN水平上是独立处理的。
Interaural time differences (ITD) and interaural level differences (ILD) both signal horizontal sound source location. To achieve a unified percept of our acoustic environment, these two cues require integration. In the present study, we tested this integration of ITD and ILD with electroencephalography (EEG) by measuring the mismatch negativity (MMN). The MMN can arise in response to spatial changes and is at least partly generated in auditory cortex. In our study, we aimed at testing for an MMN in response to stimuli with counter-balanced ITD/ILD cues. To this end, we employed a roving oddball paradigm with alternating sound sequences in two types of blocks: (a) lateralized stimuli with congruently combined ITD/ILD cues and (b) midline stimuli created by counter-balanced, incongruently combined ITD/ILD cues. We observed a significant MMN peaking at about 112–128 ms after change onset for the congruent ITD/ILD cues, for both lower (0.5 kHz) and higher carrier frequency (4 kHz). More importantly, we also observed significant MMN peaking at about 129 ms for incongruently combined ITD/ILD cues, but this effect was only detectable in the lower frequency range (0.5 kHz). There were no significant differences of the MMN responses for the two types of cue combinations (congruent/incongruent). These results suggest that—at least in the lower frequency ranges (0.5 kHz)—ITD and ILD are processed independently at the level of the MMN in auditory cortex.