Robust cortical entrainment to the speech envelope relies on the spectro-temporal fine structure.
Robust cortical entrainment to the speech envelope relies on the spectro-temporal fine structure.
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DOI：
10.1016/j.neuroimage.2013.10.054
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发表时间：
2014-03
期刊：
影响因子：
5.7
通讯作者：
Simon JZ
中科院分区：
文献类型：
--
作者：
Ding N;Chatterjee M;Simon JZ
语音识别对背景噪声具有鲁棒性。一种潜在的神经机制是听觉系统将语音与聆听背景分开并可靠地对其进行编码。这种强大的内部表征已经在听觉皮层中通过语音时间包络所夹带的神经活动得到了证明。然而，一个悖论随之出现，因为众所周知，频谱-时间精细结构而不是时间包络是将目标语音与背景噪声分离的主要线索。可靠的皮质夹带实际上是否反映了参与语音流的强大内部“合成”，而不是直接跟踪声学包络？在这里，我们通过降低谱时精细结构同时使用声码器保留时间包络来测试这一假设。脑磁图（MEG）记录显示，与自然语音的强劲夹带相比，背景噪声严重降低了声码语音的皮质夹带。此外，δ 频段（1-4 Hz）的皮质夹带可以预测个体听众水平的语音识别分数。这些结果表明，可靠的皮质对语音的夹带依赖于谱时精细结构，并表明皮质对语音包络的夹带不仅仅是语音包络的表示，而且是与语音的音节和短语节奏同步的多尺度谱时特征的连贯表示。
Speech recognition is robust to background noise. One underlying neural mechanism is that the auditory system segregates speech from the listening background and encodes it reliably. Such robust internal representation has been demonstrated in auditory cortex by neural activity entrained to the temporal envelope of speech. A paradox, however, then arises, as the spectro-temporal fine structure rather than the temporal envelope is known to be the major cue to segregate target speech from background noise. Does the reliable cortical entrainment in fact reflect a robust internal “synthesis” of the attended speech stream rather than direct tracking of the acoustic envelope? Here, we test this hypothesis by degrading the spectro-temporal fine structure while preserving the temporal envelope using vocoders. Magnetoencephalography (MEG) recordings reveal that cortical entrainment to vocoded speech is severely degraded by background noise, in contrast to the robust entrainment to natural speech. Furthermore, cortical entrainment in the delta-band (1–4 Hz) predicts the speech recognition score at the level of individual listeners. These results demonstrate that reliable cortical entrainment to speech relies on the spectro-temporal fine structure, and suggest that cortical entrainment to the speech envelope is not merely a representation of the speech envelope but a coherent representation of multiscale spectro-temporal features that are synchronized to the syllabic and phrasal rhythms of speech.
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影响因子：
25
作者：
通讯作者：
--
DOI：
10.1523/jneurosci.5297-12.2013
发表时间：
2013-03-27
期刊：
The Journal of neuroscience : the official journal of the Society for Neuroscience
影响因子：
--
作者：
Ding N;Simon JZ
通讯作者：
Simon JZ
DOI：
10.1098/rstb.2007.2160
发表时间：
2008-03-12
影响因子：
6.3
作者：
Poeppel, David;Idsardi, William J.;van Wassenhove, Virginie
通讯作者：
van Wassenhove, Virginie
影响因子：
1.7
作者：
Chait, M;Simon, JZ;Poeppel, D
通讯作者：
Poeppel, D
影响因子：
16.2
作者：
Rabinowitz NC;Willmore BD;Schnupp JW;King AJ
通讯作者：
King AJ