Skoe Erika, Burakiewicz Emily, Figueiredo Michael, Hardin Margaret
Department of Speech, Language, and Hearing Sciences, Storrs, CT 06269, USA; Affiliate of the Department of Psychological Sciences, Cognitive Sciences Program, Connecticut Institute for Brain and Cognitive Sciences, Storrs, CT 06269, USA; University of Connecticut, Storrs, CT 06269, USA.
Department of Speech, Language, and Hearing Sciences, Storrs, CT 06269, USA; University of Connecticut, Storrs, CT 06269, USA.
Neuroscience. 2017 May 4;349:278-290. doi: 10.1016/j.neuroscience.2017.02.049. Epub 2017 Mar 1.
The central auditory nervous system (CANS) undergoes language-dependent tuning to enhance linguistically relevant features of sound. However, less is known about how dual-language exposure affects the CANS. Recent reports indicate that Spanish-English bilingual children and adolescents have larger neural responses to the fundamental frequency (F0) of vowels, as measured by the frequency-following response (FFR), a phase-locked response to sound. Given the cross-language significance of F0, this led us to hypothesize that enhanced neural responses to the F0 are not unique to Spanish-English bilingual children and adolescents but are instead a common feature of a CANS with significant early dual language experience. In support of this hypothesis, we found that early bilingual adults, representing more than a dozen languages, had more robust FFRs to the F0 compared to English-language monolinguals suggesting that bilingual experience imprints on the CANS in a similar fashion regardless of the languages of exposure. Taken together, our results suggest that early exposure to two linguistic sound systems primes the brain to respond to the F0, a basic feature of all speech sounds that signals important indexical information for vowel, talker, and language identification.
中枢听觉神经系统（CANS）会进行依赖语言的调谐，以增强声音中与语言相关的特征。然而，关于双语接触如何影响CANS，我们了解得较少。最近的报告表明，西班牙裔-英语双语儿童和青少年对元音的基频（F0）有更大的神经反应，这是通过频率跟随反应（FFR）测量的，FFR是对声音的一种锁相反应。鉴于F0在跨语言方面的重要性，这使我们推测，对F0增强的神经反应并非西班牙裔-英语双语儿童和青少年所独有，而是具有早期丰富双语经验的CANS的一个共同特征。为支持这一假设，我们发现，代表十几种语言的早期双语成年人与英语单语者相比，对F0有更强健的FFR，这表明无论接触的是何种语言，双语经验都会以类似方式在CANS上留下印记。综合来看，我们的结果表明，早期接触两种语言声音系统会使大脑对F0产生反应，F0是所有语音的一个基本特征，它为元音、说话者和语言识别提供重要的索引信息。
