Collaborative Research: Direct impacts of executive functions on language comprehension: Evidence from eye movements and electrophysiology

人类在听和读的过程中面临着语言中普遍存在的歧义。例如，两个口语单词可能听起来几乎相同(例如，“海滩”和“桃子”)；句子可以通过多种方式进行语法分析；语音经常被环境声音所掩盖，就像在拥挤的餐馆里一样。尽管模棱两可通常会增加对信息做出错误解释甚至无法解释的风险，但健康的年轻人在理解语言方面非常熟练，尽管机器学习取得了重大进展，但他们的能力远远超过了自动系统。解释人类如何在模棱两可的情况下理解语言，以及为什么有些人会失败，这是认知科学的一个根本性挑战，对于帮助有语言障碍的人至关重要，这些人在模棱两可的情况下会加剧，包括中风患者和患有听力损失的健康老年人。这项研究将使用先进的神经生理学和眼球跟踪方法来阐明人们如何通过执行功能(EF)来调节他们对言语和语言输入的解释。EF是一系列认知机制，能够在大脑中进行信息处理，并灵活地指导目标导向的行为。当一个句子可能有多种不同的解释时，EF被认为是帮助人们从不同的解释中进行选择的关键，当环境“嘈杂”时，EF被认为是引导大脑感知一个单词的关键。然而，人们对EF促进语言理解的神经和认知机制知之甚少。这个项目将阐明英孚在语言理解中的作用。这个项目将检验这样一种假设，即两种特殊形式的执行功能--注意力控制和认知控制--在面对歧义时，在支持语言理解方面发挥着基本而独特的作用。注意力控制被认为是通过引导对预期信号的知觉处理来调节信息的收集，在次优的倾听条件下将其与噪声隔离。认知控制的假设是，当多个线索相互竞争时，通过引导内部表征与相关证据来源相一致来帮助修正误解。研究人员将利用头皮记录的脑电中的神经振荡活动，为认知任务执行过程中的认知控制和注意力控制提供新的标记。眼动模式将被用来实时跟踪参与者对语言输入的解释，方法是记录听者在听句子和询问面前场景时的毫秒级凝视动态。脑电和眼球跟踪的结合将提供语言理解过程中神经过程和口译过程的时间性质的多模式表征。为了阐明注意力和认知控制如何分别影响人类处理歧义的能力，实验将在处理语言之前操纵这些EF亚型的参与状态，让参与者执行任务，如侧翼任务，众所周知这些任务招募认知控制过程。这一实验方法将建立EF和语言处理之间的因果关系，并将确定认知控制和注意力控制对理解的独特贡献。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Human beings confront pervasive ambiguity in language as they listen and read. For example, two spoken words can sound nearly identical (e.g., “beach” and “peach”); sentences can be grammatically analyzed in multiple ways; and speech is often obscured by environmental sounds, as in a crowded restaurant. Although ambiguity routinely increases the risk of arriving at the wrong interpretation, or even no interpretation of a message, healthy young adults are marvelously adept at understanding language, vastly surpassing the capabilities of automatic systems despite major advances in machine learning. Explaining how humans understand language in the face of ambiguity, and why some populations fail, is a fundamental challenge for cognitive science, and is crucial for assisting people with language impairments that intensify under conditions of ambiguity, including stroke patients and healthy older adults with hearing loss. This research will use advanced neurophysiological and eye-tracking methods to illuminate how people regulate their interpretations of speech and language input by using executive functions (EF): the family of cognitive mechanisms that enable information processing in the brain and the flexible guidance of goal-directed behavior. EF are thought to be critical to helping people select among different interpretations of a sentence when more than one is possible, and for guiding the mind toward perceiving a word when the environment is “noisy.” However, the neural and cognitive mechanisms that allow EF to contribute to language comprehension are poorly understood. This project will elucidate EF’s role in language comprehension. This project will test the hypothesis that two particular forms of executive function – attention control and cognitive control – play fundamental and distinct roles in supporting language comprehension in the face of ambiguity. Attention control is hypothesized to regulate the collection of information by directing perceptual processing toward the intended signal, isolating it from noise under suboptimal listening conditions. Cognitive control is hypothesized to assist the revision of misinterpretations by guiding internal representations to align with relevant sources of evidence when multiple cues compete. The investigators will use neural oscillatory activity in scalp-recorded EEG to provide novel markers of cognitive control and attention control during cognitive task performance. Eye-movement patterns will be used to track participants’ interpretations of language input in real time, by recording the millisecond-level dynamics of listeners’ gaze while they listen to sentences and interrogate a scene before them. The combination of EEG and eye tracking will provide a multi-modal characterization of the neural processes and temporal nature of interpretation procedures during language comprehension. In order to illuminate how attention and cognitive control separately affect humans’ ability to deal with ambiguity, the experiments will manipulate the engagement status of these EF subtypes just prior to processing language, by having participants perform tasks, such as the Flanker task, which are known to recruit cognitive-control processes. This experimental approach will establish causal relationships between EF and language processing and will identify the distinctive contributions of cognitive control and attention control to comprehension.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.