CAREER: The Effect of Trial-Level Lexical Entropy on Language Processing

理解和创造语言是如此平凡，以至于我们可能无法理解其中的复杂性。本质上毫无意义的语音和字母形状进入我们的耳膜或眼球，并通过一系列处理步骤在我们的大脑中转化为有意义的想法。我们可以做到这一点，尽管我们接收到的语言输入并不完美；我们在嘈杂的环境中理解语言，当面对口音等特殊因素时，我们可以适应模棱两可的单词和结构，以及许多其他因素。这些挑战不仅是由于输入的不确定性；人类的认知系统有其自身的局限性，注意力的缺失或记忆力的衰退会影响我们处理语言的方式。尽管存在这种不确定性，但为了在语言处理任务中保持成功和高效，人类大脑会根据当前环境和/或先验知识对即将到来的信息产生预测。这个项目研究了这种预测，特别关注我们如何从大量的竞争词中根据意义、词性和发音等信息挑选出想要的词的过程。具体来说，它着眼于潜在即将出现的单词的总体分布——特别是即将出现的单词的不确定性——如何影响我们感知和产生语言的能力，并以个人对世界的独特体验来衡量这种分布。就更广泛的影响而言，该项目通过开发涉及语言科学的不同部门的共同授课课程，在密西西比州立大学建立了语言科学社区，并培训来自全校的学生和教师如何使用更先进的工具来回答有关语言处理本质的各种问题。为了获得与即将到来的语言材料相关的有效、敏感和细致的不确定性测量，研究人员测量了每个研究参与者在特定句子上下文中的“信息熵”。信息熵反映了与句子上下文后面的下一个单词相关的不确定性，当对每个上下文的每个参与者进行测量时，它反映了特定语义域中特定个体所经历的不确定性，从而为每个个体提供了定制的熵度量。研究人员收集行为数据，如阅读时间，以及大脑数据，如正在进行的大脑活动和脑电图（EEG），以评估人类大脑如何对即将到来的输入产生预测。研究人员还测量了其他大脑功能，如工作记忆广度和注意力控制，以研究预测生成如何与这些功能相互作用。这个项目的结果将推进我们对预测在人类产生和理解语言时的作用的认识，以及这些技能如何与其他关键的人类大脑功能（如工作记忆和注意力）相互作用。该项目由感知、行动和认知项目、语言学项目和促进竞争研究的既定项目（EPSCoR）共同资助。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Understanding and producing language is so commonplace that we may fail to appreciate the complexities involved in them. Intrinsically meaningless speech sounds and letter shapes hit our eardrums or eyeballs, and, through a series of processing steps are turned into meaningful ideas in our heads. We can do this despite the fact that the linguistic input that we receive is not perfect; we understanding language in noisy environments, when faced with idiosyncratic factors such as accents, we can adjust to ambiguous words and structures, among many other factors. These challenges are not only due to uncertainty in the input; the human cognitive system has its own limitations, with lapses in attention or failures of memory impacting how we process language. To remain successful and efficient in tasks of language processing despite this uncertainty, the human brain generates predictions about upcoming information based on the current context and/or prior knowledge. This project investigates this prediction, specifically focusing on the process of how we pick out the intended words - based on information like meaning, part of speech, and pronunciation, among a large set of competing words. Specifically, it looks at how the overall distribution of potential upcoming words - and specifically uncertainty about upcoming words - influences our ability to perceive and produce language, measuring this distribution at the level of an individual person with their own idiosyncratic experiences of the world. In terms of broader impacts, this project builds the language science community at Mississippi State University through the development of co-taught courses across different departments engaged in language science, and training students and faculty from across the university on how to use more advanced tools to answer a variety of questions about the nature of language processing. To obtain a valid, sensitive and nuanced measure of uncertainty associated with upcoming linguistic material, the investigators measure "information entropy" for each research participant in specific sentential contexts. Information entropy reflects the uncertainty associated with the next word following a sentential context, and when measured for each participant for each context, it reflects uncertainty experienced by specific individuals in specific semantic domains, thereby providing a customized entropy measure for each individual. The investigators collect behavioral data, such as reading times, as well as brain data, such as ongoing brain activity commonly known and electroencephalogram or EEG, to assess how the human brain generates predictions about upcoming input. The investigators also measure other brain functions such as working memory span and attention control to examine how prediction generation interacts with those functions. The results of this project will advance our knowledge about the role of prediction when humans produce and comprehend language, and how those skills interact with other critical human brain functions such as working memory and attention. This project is jointly funded by the Perception, Action and Cognition program, the Linguistics program and the Established Program to Stimulate Competitive Research (EPSCoR).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.