Department of Psychological Sciences, University of Connecticut, Storrs, Connecticut 06269.
Department of Neuropsychology and Psychopharmacology, Maastricht University, 6200 MD, Maastricht, The Netherlands.
J Neurosci. 2024 Jan 3;44(1):e0666232023. doi: 10.1523/JNEUROSCI.0666-23.2023.
Learning to process speech in a foreign language involves learning new representations for mapping the auditory signal to linguistic structure. Behavioral experiments suggest that even listeners that are highly proficient in a non-native language experience interference from representations of their native language. However, much of the evidence for such interference comes from tasks that may inadvertently increase the salience of native language competitors. Here we tested for neural evidence of proficiency and native language interference in a naturalistic story listening task. We studied electroencephalography responses of 39 native speakers of Dutch (14 male) to an English short story, spoken by a native speaker of either American English or Dutch. We modeled brain responses with multivariate temporal response functions, using acoustic and language models. We found evidence for activation of Dutch language statistics when listening to English, but only when it was spoken with a Dutch accent. This suggests that a naturalistic, monolingual setting decreases the interference from native language representations, whereas an accent in the listener's own native language may increase native language interference, by increasing the salience of the native language and activating native language phonetic and lexical representations. Brain responses suggest that such interference stems from words from the native language competing with the foreign language in a single word recognition system, rather than being activated in a parallel lexicon. We further found that secondary acoustic representations of speech (after 200 ms latency) decreased with increasing proficiency. This may reflect improved acoustic-phonetic models in more proficient listeners. Behavioral experiments suggest that native language knowledge interferes with foreign language listening, but such effects may be sensitive to task manipulations, as tasks that increase metalinguistic awareness may also increase native language interference. This highlights the need for studying non-native speech processing using naturalistic tasks. We measured neural responses unobtrusively while participants listened for comprehension and characterized the influence of proficiency at multiple levels of representation. We found that salience of the native language, as manipulated through speaker accent, affected activation of native language representations: significant evidence for activation of native language (Dutch) categories was only obtained when the speaker had a Dutch accent, whereas no significant interference was found to a speaker with a native (American) accent.
学习用外语处理语音涉及学习将听觉信号映射到语言结构的新表示。行为实验表明，即使是非常精通非母语的听众也会受到母语表示的干扰。然而，这种干扰的大部分证据来自于可能无意中增加母语竞争者显著性的任务。在这里，我们在自然故事听力任务中测试了熟练程度和母语干扰的神经证据。我们研究了 39 名母语为荷兰语的人的脑电图反应（14 名男性），这些人听了一位以美式英语或荷兰语为母语的人说的英语短篇小说。我们使用声学和语言模型，使用多变量时间响应函数来模拟大脑响应。我们发现，在听英语时，会激活荷兰语统计数据，但前提是英语是用荷兰口音说的。这表明，在自然的单语环境中，母语表示的干扰会减少，而听众自己的母语口音可能会增加母语干扰，因为这会增加母语的显著性并激活母语的语音和词汇表示。大脑反应表明，这种干扰源自母语单词与外语单词在单个单词识别系统中竞争，而不是在并行词汇中激活。我们还发现，随着熟练程度的提高，言语的次要声学表示（200 毫秒潜伏期后）减少。这可能反映了更熟练的听众中改进的声学-语音模型。行为实验表明，母语知识会干扰外语听力，但这种影响可能对任务操作敏感，因为增加元语言意识的任务也可能增加母语干扰。这突出了使用自然任务研究非母语言语处理的必要性。我们在参与者听理解时进行了毫不干扰的神经反应测量，并在多个表示层面上描述了熟练程度的影响。我们发现，母语的显著性，如通过说话者口音来操纵，会影响母语表示的激活：只有当说话者带有荷兰口音时，才会获得母语（荷兰语）类别的显著激活证据，而对于带有母语（美式英语）口音的说话者则没有发现显著干扰。
