Functional organization of the superior temporal gyrus for speech perception

描述(申请人提供)：言语感知是听者听到并解释语言声音的过程。它是由高度可变和复杂的声音信号到语音表示的唯一映射来定义的。一系列研究表明，人类的后上颞叶皮质负责语音的专门处理。虽然是局部性的，但提取语言信息的基本神经机制完全不清楚。我们提出了一种创新的方法，使用定制的颅内高密度电极阵列，在清醒状态下直接从后颞叶皮质记录详细的神经活动，行为正常的受试者接受癫痫手术的临床评估。这种方法提供了尽可能高的空间和时间分辨率，从而克服了非侵入性成像方法的许多局限性。这项研究定位在听神经科学和语言学领域之间的关键界面上。我们的 先前的结果表明，语音的皮质表征表现出与声学参数上的知觉边界相对应的重要的非线性(Chang等人，自然神经科学，2010)。在这些发现的基础上，我们提出了实验来确定：1)后颞回声学和语音特征的功能组织，2)紧急语音表征的分布式、群体水平编码，以及3)在多说话者听力环境中的“稳健”语音表征的相关性。这些拟议的实验结果将对神经语言学领域和更广泛的感觉知觉和认知研究产生重大影响。

DESCRIPTION (provided by applicant): Speech perception is the process by which listeners hear and interpret the sounds of language. It is defined by the unique mapping of a highly variable and complex acoustic signal to a phonetic representation. A convergence of studies has implicated the human posterior superior temporal cortex for the specialized processing of speech sounds. Although localized, the basic neural mechanisms by which linguistic information is extracted are entirely unclear. We propose an innovative methodological approach using customized intracranial high-density electrode arrays to record detailed neural activity directly from the posterior temporal cortex in awake, behaving subjects undergoing clinical evaluation for epilepsy surgery. This method offers the highest possible spatial and temporal resolution, thereby overcoming many limitations of non-invasive imaging approaches. This research is positioned at a critical interface between the fields of auditory neuroscience and linguistics. Our previous results demonstrate that cortical representation of speech sounds manifest important non-linearities that correspond to perceptual boundaries over acoustic parameters (Chang et al, Nature Neuroscience 2010). Building on these findings, we propose experiments to determine: 1) the functional organization of the posterior temporal gyrus for acoustic and phonetic features, 2) the distributed, population-level encoding of emergent phonetic representation, and 3) the correlates of "robust" speech representation in the context of a multi-speaker listening environment. The results of these proposed experiments will have significant impact on the field of neurolinguistics and broader research on sensory perception and cognition.