Doctoral Dissertation Research: Cross-language transfer in voice onset time: A window into perceptual adaptation in brain and behavior

博士论文研究：发声时间的跨语言迁移：了解大脑和行为知觉适应的窗口

• 批准号: 2234907
• 负责人: Janet van Hell
• 金额: $ 1.19万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-03-01 至 2025-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2234907&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Cross; language

Of all languages acquired as a second language, English has both the largest number of users (978 million) and the broadest geographic reach. In the U.S., approximately 22% of the population speaks both English and another language. Consequently, “foreign-accented” varieties of English are common. Foreign-accented varieties differ from “native-accented" varieties in several ways. This doctoral dissertation focuses on how speech sounds are pronounced by different speakers who speak English as a first or second language. Previous research has shown that listeners are able to adapt to the speech sounds of foreign-accented speech within a minute of exposure. However, how listeners acheive this rapid adaptation is still unknown. Understanding how listeners achieve this level of flexibility in speech perception is critical for informing not only linguistic theories of speech perception but also technological advances in automated speech recognition systems like the popular voice assistants Alexa and Siri. The present dissertation investigates the interface between second language speech production and first language speech perception in a series of behavioral and electrophysiological experiments.The doctoral dissertation research is guided by three research questions: (1) How does experience with Spanish-accented English facilitate later comprehension of Spanish-accented English speech? (2) How specific does this experience need to be? (3) What can time-sensitive neurocognitive measures of language processing such as electroencephalography--the measure of electrical activity at the scalp--illuminate about second language-accented speech perception? The ideal adapter framework provides a strong theoretical foundation from which to investigate the interface between second language (L2) speech production and first language (L1) speech perception. Under this framework, listeners are sensitive to the probability distributions between acoustic cues and phonetic categories. Listeners can learn the specific cue-category mappings that characterize a particular group of talkers in order to achieve robust perception. The present dissertation uses the cue-category mapping between voice onset time (VOT) and the voiceless stop consonants /p/, /t/, and /k/ as a test case for this hypothesis. Perceptual ambiguity between these voiceless stops and their voiced counterparts /b/, /d/, and /g/, respectively, due to cross-language transfer in Spanish-accented English provides a window into the adaptation process. The present dissertation uses cross-modal priming to measure adaptation to Spanish-accented /p t k/ both behaviorally and neurocognitively with electroencephalography (EEG/ERP). The researchers implement an innovative experimental design to compare the factors of (A) exposure to variability across multiple talkers with the same accent and (B) the level of similarity between the accented features encountered during the exposure phase and those encountered during the test phase. To date, these factors have not been compared directly, limiting our understanding of adaptation to L2-accented speech. In addition, the researchers use a single group of talkers across exposure conditions to control the type and amount of experience with each individual talker. Finally, this study is the first to investigate perceptual adaptation to L2-accented speech with EEG. Using this fine-grained, time-sensitive measure reveals the relative contributions of phonetic, phonological, and semantic information in resolving perceptual ambiguity in L2-accented speech.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在作为第二语言习得的所有语言中，英语拥有最多的用户（9.78亿）和最广泛的地理覆盖范围。在美国，大约22%的人口会说英语和其他语言。因此，“外国口音”的英语变体很常见。外国口音的品种在几个方面不同于“本土口音”的品种。这篇博士论文的重点是如何语音发音由不同的发言人谁说英语作为第一或第二语言。先前的研究表明，听众能够在一分钟内适应外国口音的语音。然而，听众是如何实现这种快速适应的仍然是个未知数。了解听众如何在语音感知中实现这种程度的灵活性，不仅对语音感知的语言学理论至关重要，而且对自动语音识别系统（如流行的语音助手Alexa和Siri）的技术进步也至关重要。本论文通过一系列的行为和电生理实验研究了第二语言语音产生和第一语言语音感知之间的接口，主要围绕三个问题展开：（1）西班牙口音英语的经验如何促进后来对西班牙口音英语语音的理解？(2)这种体验需要有多具体？(3)对时间敏感的语言处理神经认知测量，如脑电图--头皮电活动的测量--能说明什么关于第二语言口音的语音感知？理想的适配器框架为研究第二语言言语产生和第一语言言语感知之间的界面提供了强有力的理论基础。在此框架下，听者对声学线索和语音类别之间的概率分布非常敏感。听众可以学习特定的线索类别映射，以实现强大的感知，表征一组特定的说话者。本论文以语音起始时间（VOT）与无辅音塞音/p/、/t/和/k/之间的线索-范畴映射作为这一假设的检验案例。由于西班牙口音英语中的跨语言迁移，这些无音塞音与它们的有声对应物/B/、/d/和/g/之间的感知模糊性分别为适应过程提供了一个窗口。本论文采用跨通道启动的方法，结合脑电图（EEG/ERP），从行为和神经认知两个方面来测量对西班牙口音/p t k/的适应。研究人员实施了一项创新的实验设计，以比较（A）暴露于具有相同口音的多个说话者之间的差异性的因素，以及（B）暴露阶段遇到的口音特征与测试阶段遇到的口音特征之间的相似性水平。到目前为止，这些因素还没有被直接比较，限制了我们的理解适应L2口音的讲话。此外，研究人员还使用了一组不同暴露条件下的谈话者，以控制每个谈话者的经验类型和数量。最后，本研究首次利用脑电研究了二语口音语音的知觉适应。使用这种细粒度的，时间敏感的措施揭示了语音，音韵和语义信息在解决L2-accented speech.This奖项的感知歧义的相对贡献反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。