Department of Psychology, Swarthmore College, Swarthmore, PA, USA.
State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, China.
Brain Lang. 2022 Jul;230:105128. doi: 10.1016/j.bandl.2022.105128. Epub 2022 May 7.
Listeners regularly comprehend continuous speech despite noisy conditions. Previous studies show that neural tracking of speech degrades under noise, predicts comprehension, and increases for non-native listeners. We test the hypothesis that listeners similarly increase tracking for both L2 and noisy L1 speech, after adjusting for comprehension. Twenty-four Chinese-English bilinguals underwent EEG while listening to one hour of an audiobook, mixed with three levels of noise, in Mandarin and English and answered comprehension questions. We estimated tracking of the speech envelope in EEG for each one-minute segment using the multivariate temporal response function (mTRF). Contrary to our prediction, L2 tracking was significantly lower than L1, while L1 tracking significantly increased with noise maskers without reducing comprehension. However, greater L2 proficiency was positively associated with greater L2 tracking. We discuss how studies of speech envelope tracking using noise and bilingualism might be reconciled through a focus on exerted rather than demanded effort.
听众经常能在嘈杂的环境下理解连续的言语。先前的研究表明，在噪声环境下，言语的神经追踪会恶化，且可以预测理解能力，而非母语的听众则会增强这种追踪能力。我们检验了以下假说：在调整理解能力后，听众会针对 L2 和有噪声的母语言语同样地增强追踪。二十四名中英双语者戴着脑电图仪聆听一个小时的有声读物，读物内容混合了普通话和英语，并在三种噪声水平下播放，同时回答理解问题。我们使用多元时间反应函数（mTRF），针对每个一分钟的片段，来估计言语包络的追踪情况。与我们的预测相反，L2 的追踪明显低于 L1，而 L1 的追踪在噪声掩蔽下显著增加，而不会降低理解能力。然而，更高的 L2 熟练度与更高的 L2 追踪呈正相关。我们讨论了如何通过关注所付出的努力，而非所要求的努力，来调和使用噪声和双语的言语包络追踪研究。
