Phonetic processing areas revealed by sinewave speech and acoustically similar non-speech
Phonetic processing areas revealed by sinewave speech and acoustically similar non-speech
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DOI：
10.1016/j.neuroimage.2005.11.029
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发表时间：
2006-05-15
期刊：
影响因子：
5.7
通讯作者：
Lai, Song
中科院分区：
文献类型：
--
作者：
Benson, Randall R.;Richardson, Matthew;Lai, Song
语音感知背后的神经基础仍然没有得到很好的理解。以前，我们使用语音和非语音复杂性维度，在最早的皮层水平(AI)发现了语音和非语音处理的分离。然而，在成像研究中，语音和非语音刺激之间的声学差异扰乱了对语言-语音区域的搜索。目前，我们使用正弦波语音(SWSP)和非语音(SWnon)，用正弦波音代替语音共振峰，以便在对比语音的同时匹配声谱和时间复杂度。使用弦进度(CP)来消除听觉一致性和物体加工的影响。12名正常RH志愿者在听SWSP、SWnon、CP和按区块排列的基线状态时进行fMRI扫描。在考虑了声学调制和相干效应后，只有两个位于左侧更靠后的双侧颞上沟的脑区被发现倾向于SWSP条件。有两个区域优先对调制频率较高的刺激做出反应，其中一个区域与右侧时间音区重叠，另一个区域位于远离音区的左角回中。这些发现构成了两种亚型听性词耳聋的基础。包括听觉和非听觉区域在内的几个大脑区域更喜欢连贯的听觉刺激，并可能参与听觉物体识别。目前这项研究的设计允许分离声学时相、物体识别和语音效应，从而产生不同和重叠的成分。(C)2005 Elsevier Inc.保留所有权利。
The neural substrates underlying speech perception are still not well understood. Previously, we found dissociation of speech and nonspeech processing at the earliest cortical level (AI), using speech and nonspeech complexity dimensions. Acoustic differences between speech and nonspeech stimuli in imaging studies, however, confound the search for linguistic-phonetic regions. Presently, we used sinewave speech (SWsp) and nonspeech (SWnon), which replace speech formants with sinewave tones, in order to match acoustic spectral and temporal complexity while contrasting phonetics. Chord progressions (CP) were used to remove the effects of auditory coherence and object processing. Twelve normal RH volunteers were scanned with fMRI while listening to SWsp, SWnon, CP, and a baseline condition arranged in blocks. Only two brain regions, in bilateral superior temporal sulcus, extending more posteriorly on the left, were found to prefer the SWsp condition after accounting for acoustic modulation and coherence effects. Two regions responded preferentially to the more frequency-modulated stimuli, including one that overlapped the right temporal phonetic area and another in the left angular gyros far from the phonetic area. These findings are proposed to form the basis for the two subtypes of auditory word deafness. Several brain regions, including auditory and nonauditory areas, preferred the coherent auditory stimuli and are likely involved in auditory object recognition. The design of the current study allowed for separation of acoustic spectrotemporal, object recognition, and phonetic effects resulting in distinct and overlapping components. (c) 2005 Elsevier Inc. All rights reserved.