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

理解人类如何理解语音是一个尚未解决且具有挑战性的问题，部分原因是不同的说话者、方言和说话速度等因素给语音信号带来了大量的时间和频谱变化。本研究的重点是时间语境对词段、音节和词知觉的影响。这项研究的结果可能会为言语速度紊乱（如构音障碍、口吃、帕金森病和失语症）的治疗提供见解，为改进语音技术应用（如增强自动语音识别、更自然的计算机生成语音）提供方法，并导致与理解口语相关的大脑机制的新发现。研究人员还将让学生参与研究，包括那些主要来自本科院校的学生。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时序机制驱动。该假说认为，词汇语速的影响主要源于自上而下的、特定于言语的时间预期，而语音语速的影响则源于自下而上的、短暂的、不特定于言语的节奏预期。这一假设将通过心理声学研究、大脑活动的非侵入性测量和理论建模来评估，以确定言语时间特性的神经表征所揭示的处理特征。

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.