Prediction during Processing of Repairs in Spoken Language

每个人都熟悉口齿不清的经历。尽管他们尽了最大的努力，但平均来说，每20个单词就会产生一个“uh”或“um”这样的填充词，他们也可能会犯一个需要纠正的发音错误。先前的研究已经确定了不流畅的一些原因，并揭示了不同类型的不流畅特征。例如，患有多动症的人比使用填充语更容易产生语言错误，而那些没有多动症的人则表现出相反的模式。然而，尽管语言信号中存在这种噪音，但听众是如何理解说话者的，这一点我们知之甚少。早期的建议测试了听者必须以某种方式忽略不流畅的假设，但最近的研究表明，不流畅只是部分被抑制，这表明不流畅影响听者如何解释他们听到的句子，甚至影响他们如何评价说话者。此外，这些较新的实验表明，当听众听到一个错误的单词时，他们会用这个错误来预测说话者可能会说什么。这种预测机制之所以有用，有两个原因：首先，它可以让听者在理解说话人的意图方面有一个良好的开端；其次，如果说话者没有发现并纠正自己的错误，它可以帮助听者对话语做出更合理的解释。了解这些预测机制是如何运作的，对我们理解语言和衰老尤为重要；人们都知道，随着年龄的增长，说话的人会变得越来越不流利，这使得他们的讲话更难被理解。考虑到美国人口的老龄化，这是一个紧迫的问题。这项工作也将有助于增强语音识别设备，如果它们要在自然、自发的语音上运行，就必须对不流畅具有鲁棒性。响应语音指令的设备现在已经进入了数百万美国人的家庭和口袋，随着它们变得越来越普遍，用户将越来越期望它们能够平稳可靠地工作。这个项目将要进行的实验将使用两种互补的方法，以毫秒为单位评估人们对言语的理解：记录大脑电生理活动（EEG），以及记录在听任务时眼睛对视觉显示的运动。本实验旨在回答关于不流畅性加工过程中预测的三个核心问题：(1)听者何时开始预测？(2)预测的具体内容是什么（一个具体的词，一个一般的范畴）？(3)预测错误的后果是什么？也就是说，考虑到听众的期望并不总是与演讲者的输出相匹配，听众如何将他们的预测与任何不一致的内容协调起来？学生将接受实验心理语言学、统计学和计算方法方面的培训，从而获得设计和解释数据的经验，以及为演示和出版准备科学报告的经验。

Everyone is familiar with the experience of being disfluent. Despite their best efforts, on average speakers will produce a filler such as "uh" or an "um" every twenty words, and they may also make a speech error which will need to be repaired. Previous research has established some of the causes of disfluency and has revealed that disfluencies of different types characterize different types of speakers; for example, individuals with ADHD are more likely to produce speech errors than to use fillers, and those without ADHD show the opposite pattern. Far less is known, however, about how listeners are able to understand speakers despite the presence of this noise in the linguistic signal. Early proposals tested the hypothesis that listeners must somehow ignore disfluencies, but more recent studies show that disfluencies are only partially suppressed, indicating that disfluencies affect how listeners interpret the sentence they hear and even how they evaluate the speaker. In addition, these newer experiments show that when listeners hear a word spoken in error, they use the error to predict what the speaker is likely to say instead. This prediction mechanism is helpful for two reasons: first, because it allows the listener to get a head start on processing the speaker's intended meaning; and second, because it helps the listener come up with a more sensible interpretation of the utterance should the speaker fail to detect and correct his or her error. Understanding how these prediction mechanisms operate is especially relevant for our understanding of language and aging; speakers are known to become more disfluent as they age, making their speech harder to understand. This is a pressing concern given the aging population of the United States. This work will also help enhance speech recognition devices that must be robust to disfluency if they are to operate on natural, spontaneous speech. Devices that respond to voice commands are now in millions of Americans' homes and pockets, and as they become more common, users will increasingly come to expect them to work smoothly and reliably. The experiments that will be conducted for this project use two complementary methods for assessing people's comprehension of speech on a millisecond-by-millisecond basis: recording of brain electrophysiological activity (EEG), and recording of eye movements to visual displays presented during listening tasks. The experiments are designed to answer three core questions about prediction during processing of disfluencies: (1) When do listeners begin to predict? (2) What precisely is the content of the prediction (a specific word, a general category)? (3) What is the fate of an incorrect prediction? That is, given that listeners' expectations will not always match the speaker's output, how do listeners reconcile their prediction with any discrepant content? This project will involve students who will be trained in experimental psycholinguistics, statistics, and computational methods, allowing them to gain experience in designing and interpreting data, as well as in preparing scientific reports for presentation and publication.