Behavioral and Neurologic Factors in Speech Learning

描述(申请人提供)：本研究的重点是影响口语(语音到单词)学习的行为和神经因素，特别是成年后非母语词汇声调和辅音在单词识别中的学习。我们的行为-神经方法将使我们能够追求我们的长期目标，即通过行为训练寻求最理想的学习结果。这项拨款申请中的10项计划实验使用的技术包括行为训练、不同学习能力的学习者的神经解剖学特征，以及与学习相关的神经生理学(脑血流动力学)变化的测量。其具体目标是：1)比较非母语词汇声调和辅音训练计划的效果，这些计划强调训练刺激中的低刺激和高刺激变异性，并比较与这两个训练计划相关的神经生理学反应(通过事件相关功能磁共振测量)；2)调查是否可以通过侧重于语音(非词汇音高和辅音)学习的额外训练来补救糟糕的词汇学习，并检查与这种补救有关的神经生理学变化；以及3)表征不同能力的学习者之间的神经解剖差异。在我们新提出的口语处理和学习模型--综合口语习得网络的指导下，我们假设：1)高刺激变异性的训练是最有效的，这表明听觉联想皮质中的大脑反应增加和顶叶的招募；2)由于缺乏语音表征而导致的糟糕的单词学习，可以通过在单词学习之前进行第一次训练来建立这种表征来补救；以及3)糟糕的学习者可以通过相对较小的左侧Heschl‘s Gyrus(由灰质或白质根据声学特征驱动)来识别；但是，通过适当的补救训练仍然可以实现成功的学习。通过了解不同培训计划的有效性以及它们如何使不同学习特征的个人受益，以及通过确定不同学习者在培训前后的神经特征，我们向能够将学习者置于最具成本效益并可能导致最理想的学习结果的培训计划更近了一步。在一个日益多元化的世界里，许多人，包括成年人，都对学习一门外语感兴趣，尽管他们很难做到这一点。学习一门外语需要我们大脑中的资源，而变化是学习的结果。我们提出的研究试图了解成年人学习在单词中使用异音时大脑发生的变化，不同的训练方法对大脑有什么影响，以及为什么某些人可以更成功地学习(例如，他们在训练前后是否有不同的大脑组织)。

DESCRIPTION (provided by applicant): The proposed research focuses on the behavioral and neurologic factors influencing spoken language (sound-to-word) learning, specifically the learning of non-native lexical tones and consonants in word identification in adulthood. Our behavioral-neural approach will enable the pursuit of our long-term goal of seeking the most desirable learning outcome mediated by behavioral training. The ten planned experiments in this grant application employ techniques that include behavioral training, neuroanatomic characterizations of learners of different learning abilities, and measurements of neurophysiologic (cerebral hemodynamic) changes associated with learning. The specific aims are to: 1) Compare the efficacy of non-native lexical tone and consonant training programs that emphasize low- versus high-stimulus variability in the training stimuli, and to compare neurophysiologic responses (measured by event-related fMRI) associated with the two training programs; 2) Investigate whether poor lexical learning can be remediated by additional training that focuses on phonetic (non-lexical pitch and consonant) learning and to examine neurophysiologic changes associated with such remediation; and 3) Characterize neuroanatomic differences between learners of different abilities. Guided by our newly proposed model of spoken language processing and learning called the Integrated Spoken Language Acquisition Network, we hypothesize the following: 1) Training with high-stimulus variability is the most efficacious, which is indicated by increased brain responses in auditory association cortex and the recruitment of the parietal lobe; 2) poor word learning resulting from a lack of phonetic representation and can be remediated by first training to establish such representations before word learning; and 3) poor learners can be identified by a relatively smaller left Heschl's Gyrus (driven by grey or white matter depending on the acoustic feature); however, successful learning can still be achieved with the appropriate remedial training. By understanding the efficacy of different training programs and how they benefit individuals of different learning profiles, as well as by identifying the neural characteristics of the different learners before and after training, we move a step closer to being able to place learners into training programs that are likely to be the most cost- effective and will likely lead to the most desirable learning outcomes. In an increasingly multi-lingual/multi-cultural world, many people, including adults, are interested in learning a foreign language even though it is difficult for them to do so. Learning a foreign language requires resources in our brain and changes occur as a result of learning. Our proposed research seeks to understand the changes that occur in the brain as adults learn to use foreign sounds in words, what effects different training methods have on the brain, and why certain individuals can learn more successfully (e.g., whether they have different brain organization before and after training).