Hino Rimi, Umejima Keita, Wada Natsumi, Takei Wataru, Kawasaki Yoshiko, Sakai Kuniyoshi L
Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan.
Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Front Psychol. 2025 Aug 14;16:1582136. doi: 10.3389/fpsyg.2025.1582136. eCollection 2025.
Linguistic factors are critically involved in our conscious thinking processes, but neuroscientific evidence of their involvement is scant. To examine commonalities that underlie reasoning and language tasks, we prepared illustrative quizzes under five conditions in a Reasoning task: Context, Fill-in, Rotation, Sequence, and Analogy. These conditions differentially involved linguistic factors of the recursive, propositional, and clausal, as well as non-linguistic factors. We also used story videos in Japanese Sign Language (JSL) in a Sign task as a language comprehension task. Brain activations measured with functional magnetic resonance imaging (fMRI) were examined for native JSL signers, with the following results. First, in the comparison of the Context condition with the Fill-in condition, which controlled non-linguistic factors, multiple bilateral regions were activated, including language areas such as the left lateral premotor cortex (L. LPMC) and left inferior frontal gyrus (L. IFG). By using conjunction and region of interest analyses, we clarified two distinct systems, which were differentially recruited under the Sequence and Analogy conditions: the system (L. LPMC/dorsal IFG and right LPMC) and the system (L. IFG), respectively. Secondly, during the Sign task, we identified activations in the L. LPMC, L. IFG, and other temporal regions. Moreover, by focusing on the contextual comprehension processes in the Sign task, we found that the L. IFG and bilateral posterior temporal gyri (pTG) were commonly activated between the Sign task and Context condition. Thirdly, in the bilateral pTG, activations were selective only under the Context condition and not under the other four conditions, confirming its role as the system. We thus successfully identified three critical systems for both language and thought processes.
语言因素在我们的有意识思维过程中起着至关重要的作用，但关于它们参与其中的神经科学证据却很少。为了研究推理和语言任务背后的共性，我们在推理任务的五种条件下准备了示例测验：情境、填空、旋转、序列和类比。这些条件分别涉及递归、命题和从句的语言因素以及非语言因素。我们还在手语任务中使用了日语手语（JSL）的故事视频作为语言理解任务。对以日语手语为母语的手语者进行了功能磁共振成像（fMRI）测量的大脑激活情况检查，结果如下。首先，在控制了非语言因素的情境条件与填空条件的比较中，多个双侧区域被激活，包括左侧外侧运动前皮层（L. LPMC）和左侧额下回（L. IFG）等语言区域。通过使用联合分析和感兴趣区域分析，我们明确了两个不同的系统，它们在序列和类比条件下被不同程度地调用：分别是 系统（L. LPMC/背侧IFG和右侧LPMC）和 系统（L. IFG）。其次，在手语任务期间，我们在L. LPMC、L. IFG和其他颞叶区域发现了激活。此外，通过关注手语任务中的情境理解过程，我们发现在手语任务和情境条件之间，L. IFG和双侧后颞回（pTG）共同被激活。第三，在双侧pTG中，激活仅在情境条件下具有选择性，而在其他四种条件下则没有，这证实了其作为 系统的作用。因此，我们成功地确定了语言和思维过程的三个关键系统。
