MARCS Institute for Brain Behaviour and Development, Western Sydney University, Penrith, NSW, Australia.
School of Health and Behavioural Sciences, University of the Sunshine Coast, Sippy Downs, Australia.
Sci Rep. 2022 Aug 5;12(1):13477. doi: 10.1038/s41598-022-17401-x.
Recent research shows that adults' neural oscillations track the rhythm of the speech signal. However, the extent to which this tracking is driven by the acoustics of the signal, or by language-specific processing remains unknown. Here adult native listeners of three rhythmically different languages (English, French, Japanese) were compared on their cortical tracking of speech envelopes synthesized in their three native languages, which allowed for coding at each of the three language's dominant rhythmic unit, respectively the foot (2.5 Hz), syllable (5 Hz), or mora (10 Hz) level. The three language groups were also tested with a sequence in a non-native language, Polish, and a non-speech vocoded equivalent, to investigate possible differential speech/nonspeech processing. The results first showed that cortical tracking was most prominent at 5 Hz (syllable rate) for all three groups, but the French listeners showed enhanced tracking at 5 Hz compared to the English and the Japanese groups. Second, across groups, there were no differences in responses for speech versus non-speech at 5 Hz (syllable rate), but there was better tracking for speech than for non-speech at 10 Hz (not the syllable rate). Together these results provide evidence for both language-general and language-specific influences on cortical tracking.
最近的研究表明，成年人的神经振荡会跟踪语音信号的节奏。然而，这种跟踪是由信号的声学驱动的，还是由语言特有的处理驱动的，目前尚不清楚。在这里，我们比较了三种节奏不同的语言（英语、法语、日语）的成年母语者在其母语合成的语音包络的皮质跟踪能力，这允许分别在三种语言的主导节奏单位（分别为步长（2.5Hz）、音节（5Hz）或音步（10Hz）水平）上进行编码。这三个语言群体还用一种非母语语言波兰语和一种非语音声码器等效物进行了测试，以研究可能的不同的语音/非语音处理。结果首先表明，对于所有三个群体，皮质跟踪在 5Hz（音节率）时最为明显，但与英语和日语群体相比，法语群体在 5Hz 时的跟踪能力增强。其次，在所有群体中，对于 5Hz（音节率）的语音与非语音没有差异，但对于 10Hz（不是音节率）的语音的跟踪效果要好于非语音。这些结果共同提供了皮质跟踪既受语言一般因素影响，也受语言特定因素影响的证据。
