The neural coding of speech across human languages

项目总结 理解口语的基本机制尚不清楚。我们才刚刚开始 了解人脑如何提取最基本的语言元素(辅音和元音) 从复杂且高度可变的声学信号。传统的理论认为有一种“通用”的语音 全人类共有的清单，但这一点受到了其他更新的理论的挑战，即每种语言都有 它自己的唯一和专门的代码。语音的大脑皮层表征研究 语言很可能会阐明这个根本问题。之前的研究已经证明了上级 在语音处理中的颞叶皮质。这项工作的大部分都是用英语完成的。 不同语言个体皮质表面神经活动的直接记录 经验是一种很有前途的方法，因为它可以提供高的空间和时间分辨率。在这里，我们 建议利用获得的神经生理记录来研究语音编码的机制 在神经外科手术过程中。高密度电极阵列、先进的信号处理和直接 大脑皮层刺激将被用来解开语音的局部和群体编码 外侧颞叶皮质。我们将研究单语和双语患者的语音神经编码。 普通话、西班牙语和英语是世界上最常用的口语，具有重要的特点 基音、共振峰和时间包络的对比差异。我们将测试一个新的假设，即语音 跨语言处理将反映相关语音属性的一般听觉编码，但 处理通过特定于语言的“调优”来修改。一种跨语言的神经编码方法 语言将有力地促进我们对大脑如何处理内部声音模式变异性的理解 以及跨语言的。这将提供对听觉处理的共享机制的基本见解 以及人类依赖经验的可塑性。这一结果可能会对 开发新的语言和神经障碍诊断和康复策略(例如， 失语症、阅读障碍、自闭症)。此外，这项提议努力实现更广泛的多样性和 包含在语言的神经科学中。

PROJECT SUMMARY The basic mechanisms underlying comprehension of spoken language are unknown. We are only beginning to understand how the human brain extracts the most fundamental linguistic elements (consonants and vowels) from a complex and highly variable acoustic signal. Traditional theories have posited a ‘universal’ phonetic inventory shared by all humans, but this has been challenged by other newer theories that each language has its own unique and specialized code. An investigation of the cortical representation of speech sounds across languages can likely shed light on this fundamental question. Previous research has implicated the superior temporal cortex in the processing of speech sounds. Most of this work has been entirely carried out in English. The recording of neural activity directly from the cortical surface from individuals with different language experience is a promising approach since it can provide both high spatial and temporal resolution. Here, we propose to examine the mechanisms of phonetic encoding, by utilizing neurophysiological recordings obtained during neurosurgical procedures. High-density electrode arrays, advanced signal processing, and direct electrocortical stimulation will be utilized to unravel both local and population encoding of speech sounds in the lateral temporal cortex. We will examine neural encoding of speech in patients who are monolingual and bilingual in Mandarin, Spanish, and English, the most common spoken languages worldwide and feature important contrastive differences of pitch, formant, and temporal envelope. We will test a novel hypothesis that speech processing across languages will reflect a general auditory encoding of relevant phonetic properties, but that processing is modified by language-specific “tuning”. A cross-linguistic approach to the neural encoding of speech will powerfully advance our understanding of how the brain processes sound pattern variability within and across languages. This will provide fundamental insights into the shared mechanisms of auditory processing and experience-dependent plasticity in humans. The results may have significant implications for the development of new diagnostic and rehabilitative strategies for language and neurological disorders (e.g., aphasia, dyslexia, autism). Furthermore, this proposal strives to achieve a broader view of diversity and inclusion in the neuroscience of language.