Liu Yang, Gao Chenyang, Wang Peng, Friederici Angela D, Zaccarella Emiliano, Chen Luyao
Max Planck Partner Group, School of International Chinese Language Education, Beijing Normal University, Beijing, China.
School of Global Education and Development, University of Chinese Academy of Social Sciences, Beijing, China.
Front Psychol. 2023 May 23;14:1151518. doi: 10.3389/fpsyg.2023.1151518. eCollection 2023.
Human language allows us to generate an infinite number of linguistic expressions. It's proposed that this competence is based on a binary syntactic operation, , combining two elements to form a new constituent. An increasing number of recent studies have shifted from complex syntactic structures to two-word constructions to investigate the neural representation of this operation at the most basic level.
This fMRI study aimed to develop a highly flexible artificial grammar paradigm for testing the neurobiology of human syntax at a basic level. During scanning, participants had to apply abstract syntactic rules to assess whether a given two-word artificial phrase could be further merged with a third word. To control for lower-level template-matching and working memory strategies, an additional non-mergeable word-list task was set up.
Behavioral data indicated that participants complied with the experiment. Whole brain and region of interest (ROI) analyses were performed under the contrast of "structure > word-list." Whole brain analysis confirmed significant involvement of the posterior inferior frontal gyrus [pIFG, corresponding to Brodmann area (BA) 44]. Furthermore, both the signal intensity in Broca's area and the behavioral performance showed significant correlations with natural language performance in the same participants. ROI analysis within the language atlas and anatomically defined Broca's area revealed that only the pIFG was reliably activated.
Taken together, these results support the notion that Broca's area, particularly BA 44, works as a combinatorial engine where words are merged together according to syntactic information. Furthermore, this study suggests that the present artificial grammar may serve as promising material for investigating the neurobiological basis of syntax, fostering future cross-species studies.
人类语言使我们能够生成无数的语言表达。有人提出，这种能力基于一种二元句法操作，即将两个元素组合形成一个新的成分。最近越来越多的研究从复杂的句法结构转向双词结构，以在最基本的层面上研究这种操作的神经表征。
这项功能磁共振成像（fMRI）研究旨在开发一种高度灵活的人工语法范式，用于在基本层面上测试人类句法的神经生物学。在扫描过程中，参与者必须应用抽象的句法规则来评估给定的双词人工短语是否可以进一步与第三个词合并。为了控制较低层次的模板匹配和工作记忆策略，还设置了一个额外的不可合并词列表任务。
行为数据表明参与者遵守了实验要求。在“结构>词列表”的对比下进行了全脑和感兴趣区域（ROI）分析。全脑分析证实了后下额叶回（pIFG，对应于布罗德曼区域（BA）44）有显著参与。此外，布罗卡区的信号强度和行为表现与同一参与者的自然语言表现均显示出显著相关性。在语言图谱和解剖学定义的布罗卡区内进行的ROI分析表明，只有pIFG被可靠激活。
综上所述，这些结果支持了这样一种观点，即布罗卡区，特别是BA 44，起着组合引擎的作用，单词根据句法信息在此合并在一起。此外，这项研究表明，目前的人工语法可能是研究句法神经生物学基础的有前途的材料，有助于未来的跨物种研究。
