Neocortical Mechanisms of Categorical Speech Perception

口语理解的基本机制尚不清楚。我们不明白， 例如，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中分离。大脑皮层代表性的研究 在分类感知期间的语音可能会揭示这个基本问题。分类 感知发生在感知到诸如沿沿着连续统的音位对比度的变量的变化时， 不是一个渐进的功能，而是一个离散的类别变化。先前的研究表明， 处理语音的上级颞叶皮层然而，大脑皮层实际上是如何代表 (i.e.编码）音素是不确定的，这主要是由于非侵入性记录技术的限制。 直接从皮层表面记录神经活动是一种很有前途的方法， 高空间和时间分辨率。在这里，我打算研究直言的机制 利用神经外科手术期间获得的神经生理学记录进行处理。的 独立ROO阶段的主要焦点将是阐明 在上级颞叶脑回中的音素，是范畴知觉的基础。高密度电极 然而，先进的信号处理和直接的皮层电刺激将被用来解开局部和局部的神经系统。 语音在颞叶外侧皮层的群体编码以及跨皮层的整体处理， 多个感觉和认知区域。

The basic mechanisms underlying comprehension of spoken language are unknown. We do not understand, for example, how the human brain extracts the most fundamental linguistic elements (consonants and vowels) from a complex and highly variable acoustic signal. An investigation of the cortical representation of speech sounds during categorical perception can likely shed light on this fundamental question. Categorical perception occurs when a change in a variable such as phonem ic contrast along a continuum is perceived, not as a gradual function but rather as a discrete category change. Previous research has implicated the superior temporal cortex in the processing Of speech sounds. However, how the cortex actually represents (i.e. encodes) phonemes is undetermined, mainly due to limitations of non-invasive recording techniques. The recording of neural activity di rectly from the cortical surface is a promising approach si nee it can provide both high spatial and temporal resolution. Here, I propose to examine the mechanisms of categorical speech processing by utilizing neurophysiological recordings obtained during ne urosurgical pnacedures. The principal focus of the independent ROO phase wil I be to elucidate the emergent invariant representation of phonemes in the superior tem poral gyrus that underiies categorical perception. High-density electrode anays, advanced signal processing, and direct eiectrocortical stim ulation will be utilized to unravel both local population encoding of speec h sounds in the lateral temporal cortex as well as global processing across multiple sensory and cognitiv e areas.