Collaborative Research: Making words disappear or appear: A neurocognitive and behavioral investigation of effects of speech rate on spoken word perception

理解人类如何理解语音是一个尚未解决的挑战性问题，部分原因是不同的说话者，方言和说话速率等因素将大量的时间和频谱变化引入语音信号。本研究的重点是时间语境对片段、音节和单词感知的影响。研究结果可以提供对涉及语速中断的疾病的治疗的见解（例如，构音障碍、口吃、帕金森病和失语症），提供改进语音技术应用的方法（例如，增强的自动语音识别，听起来更自然的计算机生成的语音），并导致与理解口语有关的大脑机制的新发现。研究人员还将让学生参与这项研究，包括来自一所主要是本科院校的学生。研究人员将测试对言语感知中时间现象的不同解释。他们提出了两种相互作用的认知机制，在词汇和语音水平上控制现象，每一种机制都由不同的神经计时机制驱动。该假设是，词汇率的影响主要源于自上而下，语音特定的时间预期，而语音率的影响起源于自下而上，短暂的节奏预期，不是特定的语音。这一假设将评估使用心理声学研究，非侵入性措施的大脑活动，和理论建模，以确定的处理特征所揭示的神经表征的时间特性的讲话。

Understanding how humans comprehend speech is an unsolved and challenging problem, in part because factors such as different speakers, dialects, and speaking rates introduce a great deal of temporal and spectral variability into the speech signal. The focus of this research is on the influence of temporal context on perception of segments, syllables, and words. Results of the research may offer insights into treatment of disorders that involve disruption of speech rate (e.g., dysarthria, stuttering, Parkinson's disease, and aphasia), inform approaches to improve speech technology applications (e.g., enhanced automatic speech recognition, more natural sounding computer-generated speech), and lead to new discoveries related to brain mechanisms involved in understanding spoken language. The investigators will also involve students in the research, including those from a primarily undergraduate institution collaborating on the project.The investigators will test different accounts of temporal phenomena in the perception of speech. They propose two interacting cognitive mechanisms controlling phenomena at lexical and phonetic levels, each driven by a different neural timing mechanism. The hypothesis is that effects of lexical rate primarily stem from top-down, speech-specific temporal expectancies, while phonetic rate effects originate in bottom-up, transient rhythmic expectations that are not specific to speech. This hypothesis will be assessed using psychoacoustic studies, non-invasive measures of brain activity, and theoretical modeling in order to identify the processing characteristics revealed by neural representations of temporal properties of speech.