The Biorobotics Institute and Department of Excellence in AI and Robotics, Scuola Superiore Sant'Anna, Pisa, Italy.
Translational Neural Engineering Laboratory, Center for Neuroprosthetics and Institute of Bioengineering, EPFL - Campus Biotech, Geneve, Switzerland.
Sci Rep. 2020 May 5;10(1):7537. doi: 10.1038/s41598-020-64375-9.
Syntax is a species-specific component of human language combining a finite set of words in a potentially infinite number of sentences. Since words are by definition expressed by sound, factoring out syntactic information is normally impossible. Here, we circumvented this problem in a novel way by designing phrases with exactly the same acoustic content but different syntactic structures depending on the other words they occur with. In particular, we used phrases merging an article with a noun yielding a Noun Phrase (NP) or a clitic with a verb yielding a Verb Phrase (VP). We performed stereo-electroencephalographic (SEEG) recordings in epileptic patients. We measured a different electrophysiological correlates of verb phrases vs. noun phrases in multiple cortical areas in both hemispheres, including language areas and their homologous in the non-dominant hemisphere. The high gamma band activity (150-300 Hz frequency), which plays a crucial role in inter-regional cortical communications, showed a significant difference during the presentation of the homophonous phrases, depending on whether the phrase was a verb phrase or a noun phrase. Our findings contribute to the ultimate goal of a complete neural decoding of linguistic structures from the brain.
语法是人类语言的一种特定于物种的成分，它将有限的单词组合成潜在无限数量的句子。由于单词的定义是通过声音表达的，因此通常不可能提取出语法信息。在这里，我们通过一种新颖的方式解决了这个问题，设计了具有完全相同声学内容但根据它们出现的其他单词具有不同语法结构的短语。具体来说，我们使用短语将冠词与名词组合成名词短语 (NP)，或将词缀与动词组合成动词短语 (VP)。我们在癫痫患者中进行了立体脑电图 (SEEG) 记录。我们在双侧半球的多个皮质区域测量了动词短语与名词短语的不同电生理相关性，包括语言区域及其在非优势半球的同源区域。高伽马波段活动（150-300 Hz 频率）在区域间皮质通讯中起着至关重要的作用，在呈现同音字短语时表现出显著差异，具体取决于短语是动词短语还是名词短语。我们的发现有助于实现从大脑中完全解码语言结构的最终目标。
