Doctoral Dissertation Research:Modeling temporal coordination in speech production using an artificial central pattern generator neural network

这个项目研究了如何在语音产生中协调时间，以及如何使用人工神经网络对这种协调进行计算建模。研究表明，语音节奏反映了语音单位（音节，重音单位，短语）的多层次，层次组织，本质上是循环的。一种具有这些特性的神经网络，即中央模式发生器（CPG），被认为是语音计时的基础。该项目提出了两个语音生产实验，旨在调查时间协调内和三个层次的语音单位在法语和英语，不同的节奏类型的语言，并发现他们共享的时间属性，哪些是语言特定的。一个三级CPG型人工神经网络，这是用来模拟两个实验的结果，以测试这样的模型来模拟两种节奏不同的语言的计时行为的能力。实验一通过比较两种语言中短语重音和短语末音节延长的持续时间效应，考察短语、重音单位和音节之间的协调性。实验2通过测量重复多次的短语的发音时间的变化，比较了两种语言中口语短语及其组成部分的整体时间协调性。拟议研究和建模工作的主要目标是调查语音单元分层结构级别之间的时间协调，特别是语言之间的协调如何变化，并测试一个生物CPG的能力-类型的神经网络模型来模拟这种协调和由此产生的语音模式。这项工作有助于理解节奏单位的协调和计时，以及大脑是如何产生这种协调的。 在其更广泛的影响，它将使言语产生的理论与其他运动行为的生物和认知模型的整合，并有助于建立语音，语言韵律，更广泛的研究之间的联系，动物行为的神经模型。这项工作也将有助于建立一个统一的模式的节奏和韵律，这是足以解释双方的普遍性和变化的人类语言。该项目还将丰富研究生合作PI的培训。

This project investigates how timing is coordinated in speech production and how this coordination can be computationally modeled using artificial neural networks. Research has shown that speech rhythm reflects a multi-tiered, hierarchical organization of speech units (syllables, accentual units, phrases) that are essentially cyclical in nature. One type of neural network which shares these properties, the central pattern generator (CPG), has been hypothesized to underlie speech timing. This project presents two speech production experiments designed to investigate temporal coordination within and among three levels of speech units in French and English, languages with distinct rhythm types, and to discover which timing properties they share and which are language-specific. A three-level CPG-type artificial neural network is presented which is used to model the results of both experiments in order to test the ability of such a model to simulate the timing behavior of two rhythmically distinct languages. Experiment 1 focuses on the coordination between phrases, accentual units, and syllables through a comparison of the durational effects of lengthening due to phrasal stress and phrase-final syllable lengthening in both languages. Experiment 2 compares the overall temporal coordination of spoken phrases and their constituent parts in the two languages by measuring the changes in articulatory timing of phrases which are repeated multiple times. The main goals of the proposed studies and modeling work are to investigate temporal coordination between the hierarchically structured levels of speech units, specifically how that coordination varies between languages, and to test the ability of a biologically inspired CPG-type neural network model to model this coordination and the speech patterns that result from it.This work contributes to an understanding of the coordination and timing of rhythm units in speech and how that coordination may be generated by the brain. In its broader impact, it will enable the integration of theories of speech production with other motor behavior in biological and cognitive models, and help to forge links between research on speech, linguistic prosody, and more broadly, neural models of animal behavior. This work will also contribute to the construction of a unified model of rhythm and prosody which is sufficient to explain both the underlying universalities and the variations of human language. The project will also enrich the training of the graduate student co-PI.