Department of Electrical Engineering, Columbia University, New York, NY, USA.
Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA.
Nat Hum Behav. 2023 May;7(5):740-753. doi: 10.1038/s41562-023-01520-0. Epub 2023 Mar 2.
The precise role of the human auditory cortex in representing speech sounds and transforming them to meaning is not yet fully understood. Here we used intracranial recordings from the auditory cortex of neurosurgical patients as they listened to natural speech. We found an explicit, temporally ordered and anatomically distributed neural encoding of multiple linguistic features, including phonetic, prelexical phonotactics, word frequency, and lexical-phonological and lexical-semantic information. Grouping neural sites on the basis of their encoded linguistic features revealed a hierarchical pattern, with distinct representations of prelexical and postlexical features distributed across various auditory areas. While sites with longer response latencies and greater distance from the primary auditory cortex encoded higher-level linguistic features, the encoding of lower-level features was preserved and not discarded. Our study reveals a cumulative mapping of sound to meaning and provides empirical evidence for validating neurolinguistic and psycholinguistic models of spoken word recognition that preserve the acoustic variations in speech.
人类听觉皮层在表示语音以及将其转化为意义方面的精确作用尚未完全被理解。在这里，我们使用神经外科患者的听觉皮层的颅内记录，让他们聆听自然语言。我们发现了一种明确的、时间有序的、解剖分布的神经编码，包含了多种语言特征，包括语音、词前音位学、单词频率以及词汇-音位和词汇-语义信息。基于其编码的语言特征对神经位点进行分组，揭示了一种层级模式，其中词前和词后的特征具有不同的表示，分布在各个听觉区域。虽然具有较长反应潜伏期和距初级听觉皮层较远的位点编码了更高层次的语言特征，但较低层次特征的编码得以保留，并未被丢弃。我们的研究揭示了从声音到意义的累积映射，并为验证保留了言语中声音变化的神经语言学和心理语言学的口语识别模型提供了经验证据。
