Cortical Tracking of Speech in Delta Band Relates to Individual Differences in Speech in Noise Comprehension in Older Adults.
Cortical Tracking of Speech in Delta Band Relates to Individual Differences in Speech in Noise Comprehension in Older Adults.
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DOI：
10.1097/aud.0000000000000923
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发表时间：
2020-08
期刊：
影响因子：
3.7
通讯作者：
Jacie R. McHaney;G. Gnanateja;Kirsten E. Smayda;Benjamin D. Zinszer;B. Chandrasekaran
中科院分区：
文献类型：
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作者：
Jacie R. McHaney;G. Gnanateja;Kirsten E. Smayda;Benjamin D. Zinszer;B. Chandrasekaran
目的在恶劣的听力环境中理解言语对老年人来说是一项挑战。纯音平均数和工作记忆的个体差异被认为是噪音理解中语音的关键指标。最近的研究表明，通过将语音分割成单词和短语(增量，1到4赫兹)或音素和音节(塞塔，4到8赫兹)，跟踪皮层振荡中的语音包络可能是与语音理解相关的重要机制。本研究的目的是调查老年人在纯音平均数、工作记忆和语音包络的皮质追踪方面的个体差异与噪声理解中语音的关系。设计使用脑电图仪对老年人(60至80岁)的连续言语皮质追踪进行评估。参与者在安静和有噪音的情况下听讲话(时间反转的讲话)，并回答理解问题。受试者完成前向数字广度和后向数字广度作为工作记忆的测量，并收集纯音平均值。噪声减少指数(RIN)是通过归一化安静和噪声中的原始皮质跟踪之间的差值来计算的。结果安静条件下的理解问题成绩高于噪声条件下的理解问题成绩。在控制纯音平均数和工作记忆的个体差异的影响的同时，评估了RIN和语音在噪声理解中的关系。在噪声理解中，Delta频段的RIN与语音有关，而Theta频段的RIN则不相关。结论利用Delta振荡进行大脑皮层跟踪对噪声的影响具有较强的鲁棒性。这些发现表明，增量频段RIN的大小与老年人在噪声理解中的语音个体差异有关。除了纯音平均数和工作记忆的影响外，Delta频段RIN可能在噪声理解中作为语音的神经度量。
OBJECTIVES Understanding speech in adverse listening environments is challenging for older adults. Individual differences in pure tone averages and working memory are known to be critical indicators of speech in noise comprehension. Recent studies have suggested that tracking of the speech envelope in cortical oscillations <8 Hz may be an important mechanism related to speech comprehension by segmenting speech into words and phrases (delta, 1 to 4 Hz) or phonemes and syllables (theta, 4 to 8 Hz). The purpose of this study was to investigate the extent to which individual differences in pure tone averages, working memory, and cortical tracking of the speech envelope relate to speech in noise comprehension in older adults. DESIGN Cortical tracking of continuous speech was assessed using electroencephalography in older adults (60 to 80 years). Participants listened to speech in quiet and in the presence of noise (time-reversed speech) and answered comprehension questions. Participants completed Forward Digit Span and Backward Digit Span as measures of working memory, and pure tone averages were collected. An index of reduction in noise (RIN) was calculated by normalizing the difference between raw cortical tracking in quiet and in noise. RESULTS Comprehension question performance was greater for speech in quiet than for speech in noise. The relationship between RIN and speech in noise comprehension was assessed while controlling for the effects of individual differences in pure tone averages and working memory. Delta band RIN correlated with speech in noise comprehension, while theta band RIN did not. CONCLUSIONS Cortical tracking by delta oscillations is robust to the effects of noise. These findings demonstrate that the magnitude of delta band RIN relates to individual differences in speech in noise comprehension in older adults. Delta band RIN may serve as a neural metric of speech in noise comprehension beyond the effects of pure tone averages and working memory.