Predicting Speech: Cortical Oscillations and Dynamics

言语是一种复杂多变的媒介，然而当我们用母语听时，理解似乎毫不费力，而且是自动的。同时，通过使用母语的经验，我们对它在声音、单词和句子的层次上是如何构成的有了丰富的知识。最近的工作已经开始强调这种知识在实时语言处理中的重要性。在语言分析的各个层面上，利用我们对语言结构的先验知识来预测即将到来的信息，从而促进对未来信息的处理，这是一种可以塑造语言理解毫不费力性质的总体机制。我的五年研究计划是确定这种预测是如何在语言感知的时间和空间动态的神经振荡中编码的：语言理解的最早阶段。特别是，这项研究建立在最近发现的基础上，这些发现已经确定了语音感知过程中预测的大脑标记。

Speech is a complex and variable medium, and yet when we listen in our native language, comprehension appears effortless and automatic. Simultaneously, through experience with our native language, we have a wealth of knowledge about how it is structured at the level of sounds, words, and sentences. Recent work has begun to emphasize the importance of this knowledge during real-time language processing. One overarching mechanism that could shape the effortless nature of language comprehension is leveraging prior knowledge of our language's structure to predict upcoming information at all levels of linguistic analysis, thereby facilitating the processing of future information. My five-year research program is to identify how this prediction is encoded in the temporal and spatial dynamics of neural oscillations during speech perception: the earliest stages of language comprehension. In particular, this research builds on recent findings which have identified a brain marker of prediction during speech perception. My long-term research goal is to incorporate findings from linguistics with cognitive neuroscience to understand the brain bases of speech perception. My short-term research goals focus on the “when”, “what” and “where” of prediction during speech perception and are centred around the following three research objectives: 1. Spatial Localization of Prediction: Where in the brain is this brain marker for prediction, does it overlap with other networks involved in speech perception, and how does it relate to other indices of speech recognition? 2. Speech Cues that Drive Prediction: What aspects of speech sound representations contribute to driving this predictive mechanism? While my previous work has demonstrated a role for the contrastive articulatory properties of speech sounds, could other cues also be at play, including speech sound co-occurrences, statistical cues, and word structure? 3. Language Specificity of Prediction: Are these predictive mechanisms general or do they rely solely on the linguistic properties of speech sounds: music vs. speech, different speakers, different speaking rates? Is the prediction of different types of information encoded in distinct oscillatory brain patterns? This research has applications for the construction of biologically plausible circuits that model language processing, necessary for Artificial Intelligence research, aid in the rehabilitation of various speech language motor-deficits by pinpointing the relevant speech properties necessary for the accurate perception and production, as well as in aphasias, where the deficit may partially result from an inability of aphasic brains to synchronize speech cues when talking to another individual, the latter two having major impacts in Canada both as we become more sensitive to speech-motor deficits in children and as our population ages, and with it, the number of cases of aphasia.