Doctoral Dissertation Research: Nonnative Phonetic Perception in Adult L2 Learners

即使经过多年的练习，成人学习者在感知和发出第二语言(L2)的声音方面也存在困难。与儿童相比，成年人往往需要更有针对性和更有针对性的输入来实现母语声音的感知和产生。本研究旨在阐明母语语音影响二语认知的机制，这种认知的神经基础，学习者差异如何影响学习，以及不同的训练模式如何调节二语语音感知的神经和行为基础。这项工作有可能明确哪些机制影响第二语言的声音感知，以及不同类型的反馈和教学如何帮助学习者更好地感知差异，从而在课堂和浸入式环境中进行更好的第二语言教学。本研究将让来自英语和西班牙语两个母语说话者群体的参与者参加为期五天的培训范例，在此期间，他们将学习区分不属于第一语言发音类别的印地语发音。在五天的时间里，参与者将完成头皮脑电(EEG)记录、基线辨别任务、训练以及几项记忆和注意力个人测量。研究人员预计，L1将在声音开始后大约150-200ms调制被称为失配负波(MMN)的脑电波形。这项测量是早期语音学习的指标，先前的研究表明，波形的幅度可以随着新的语音学习而改变或移动，这表明早期的声学和语音处理随着新的输入而重组。此外，研究人员将研究母语以及不同的训练和反馈范式如何影响这种MMN变化。这些分析将突出以前未曾探索过的二语行为和神经加工方面的差异，这些差异源于先前的第一语言知识和表征。此外，最后的分析将通过将行为训练中的表现与神经反应联系起来，将行为和神经测量联系起来，以调查成人第二语言语音习得的时间进程。通过运用行为学和神经学的方法来探讨母语对非母语语音知觉的影响(这是第一个考察和阐明语音习得时间过程的训练范式)，这项工作将为第二语言感知和习得模型提供有价值的信息，并为第二语言语音对比教学提供相关数据。

Even with years of practice, adult learners have trouble perceiving and producing sounds in a second language (L2). Adults tend to need more focused and targeted input to achieve native-like perception and production of L2 sounds than do children. The work proposed here aims to clarify the mechanisms through which L2 perception is influenced by first language (L1) sounds, the neural basis of this perception, how learner differences can influence learning, and how different training paradigms modulate both the neural and behavioral basis of L2 sound perception. This work has the potential to clarify specifically what mechanisms affect L2 sound perception and how different types of feedback and instruction can help learners perceive differences better, allowing for better L2 instruction in the classroom and immersion settings.This study will have participants from two native speaker groups, English and Spanish, participate in a five-day training paradigm during which they will learn to discriminate Hindi sounds that do not belong to their L1 sound categories. During the five days, participants will come in to complete electroencephalogram (EEG) recordings from the scalp, baseline discrimination tasks, training, and several memory and attention individual measures. The researchers expect that the L1 will modulate the EEG waveform known as the mismatch negativity (MMN) at approximately 150-200ms after sound onset. This measure indexes early phonetic learning and previous research has shown that the waveform's amplitude can change or shift with new phonetic learning, indicating a reorganization of early acoustic and phonetic processing with new input. Furthermore, the researchers will examine how the L1 and different training and feedback paradigms influence this MMN change. The analyses will highlight previously unexplored differences in L2 behavioral and neural processing that arise from prior L1 knowledge and representations. Furthermore, final analyses will link behavioral and neural measures by correlating performance during behavioral training with neural responses to investigate the time course of adult L2 phonetic acquisition. By using both behavioral and neural methods to explore the effects of L1 influence on nonnative phonetic perception (in the first such training paradigm to examine and clarify the time course of phonetic acquisition), this work will contribute valuable information for models of L2 perception and acquisition, and relevant data for the instruction and teaching of L2 sound contrasts.