Degradation levels of continuous speech affect neural speech tracking and alpha power differently.
Degradation levels of continuous speech affect neural speech tracking and alpha power differently.
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DOI：
10.1111/ejn.14912
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发表时间：
2022-06
影响因子：
3.4
通讯作者：
Weisz, Nathan
中科院分区：
文献类型：
--
作者：
Hauswald, Anne;Keitel, Anne;Chen, Ya-Ping;Roesch, Sebastian;Weisz, Nathan
理解一个糟糕的听觉信号可能是一个挑战。以前试图用神经术语量化语音可懂度的尝试通常集中在两种测量方法之一，即低频语音-大脑同步或α功率调制。然而，关于这些措施的调整情况的报告褒贬不一，而这些措施通常被单独研究，这一事实加剧了这一问题。我们提出了两个MEG研究分析这两种措施。在研究1中，参与者听取了三种不同程度的退化（原始，7通道和3通道声码）的单峰听觉语音。清晰度随着清晰度的下降而下降，但即使在最低清晰度水平（3通道声码）下，语音在一定程度上仍然可以理解。低频（1-7 Hz）语音跟踪表明，在双侧听觉和左额叶区域中，中度退化语音（7通道）的影响最大，呈U形关系。为了跟进这一发现，我们在第二项MEG研究中实施了三个额外的声码水平（5通道，2通道和1通道）。使用这种更大范围的退化，语音-大脑同步显示出与研究1相似的模式，但进一步表明，当语音变得无法理解时，同步再次下降。α功率的关系不同，它在声码水平上继续下降，达到5声道声码的地板效应。预测主观可懂度的基础上，无论是结合两种措施或每一个措施单独的模型显示了组合模型的优越性。我们的研究结果强调，语音跟踪和阿尔法功率被修改不同的程度的连续语音的退化，但共同有助于主观的语音理解。记录脑磁图，同时提出连续语音在不同程度的退化表明，阿尔法功率和语音跟踪不同的影响。虽然阿尔法功率随着清晰度的下降而下降，但语音跟踪遵循倒U形。线性混合模型表明，阿尔法功率和跟踪的组合有助于主观语音理解。
Making sense of a poor auditory signal can pose a challenge. Previous attempts to quantify speech intelligibility in neural terms have usually focused on one of two measures, namely low‐frequency speech‐brain synchronization or alpha power modulations. However, reports have been mixed concerning the modulation of these measures, an issue aggravated by the fact that they have normally been studied separately. We present two MEG studies analyzing both measures. In study 1, participants listened to unimodal auditory speech with three different levels of degradation (original, 7‐channel and 3‐channel vocoding). Intelligibility declined with declining clarity, but speech was still intelligible to some extent even for the lowest clarity level (3‐channel vocoding). Low‐frequency (1–7 Hz) speech tracking suggested a U‐shaped relationship with strongest effects for the medium‐degraded speech (7‐channel) in bilateral auditory and left frontal regions. To follow up on this finding, we implemented three additional vocoding levels (5‐channel, 2‐channel and 1‐channel) in a second MEG study. Using this wider range of degradation, the speech‐brain synchronization showed a similar pattern as in study 1, but further showed that when speech becomes unintelligible, synchronization declines again. The relationship differed for alpha power, which continued to decrease across vocoding levels reaching a floor effect for 5‐channel vocoding. Predicting subjective intelligibility based on models either combining both measures or each measure alone showed superiority of the combined model. Our findings underline that speech tracking and alpha power are modified differently by the degree of degradation of continuous speech but together contribute to the subjective speech understanding. Recording magnetoencephalography while presenting continuous speech under different levels of degradation shows that alpha power and speech tracking are differently affected. While alpha power declines with declining clarity speech tracking follows an inverted U‐shape. Linear mixed models suggest that a combination of alpha power and tracking contribute to subjective speech understanding.
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影响因子：
9.8
作者：
Gross J;Hoogenboom N;Thut G;Schyns P;Panzeri S;Belin P;Garrod S
通讯作者：
Garrod S
影响因子：
5.3
作者：
Eisner, Frank;McGettigan, Carolyn;Scott, Sophie K.
通讯作者：
Scott, Sophie K.
影响因子：
2.5
作者：
Horton, Cort;D'Zmura, Michael;Srinivasan, Ramesh
通讯作者：
Srinivasan, Ramesh
DOI：
10.1016/j.cub.2018.03.044
发表时间：
2018-05-07
期刊：
Current biology : CB
影响因子：
--
作者：
Hauswald A;Lithari C;Collignon O;Leonardelli E;Weisz N
通讯作者：
Weisz N
影响因子：
4.3
作者：
Chandrasekaran C;Trubanova A;Stillittano S;Caplier A;Ghazanfar AA
通讯作者：
Ghazanfar AA