Center for MRI Research, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China, 100871.
Department of Linguistics, the University of Hong Kong, Hong Kong, China, 999077.
J Neurosci. 2021 Apr 28;41(17):3854-3869. doi: 10.1523/JNEUROSCI.2771-20.2021. Epub 2021 Mar 9.
The integral capacity of human language together with semantic memory drives the linkage of words and their meaning, which theoretically is subject to cognitive control. However, it remains unknown whether, across different language modalities and input/output formats, there is a shared system in the human brain for word-meaning binding and how this system interacts with cognitive control. Here, we conducted a functional magnetic resonance imaging experiment based on a large cohort of subjects (50 females, 50 males) to comprehensively measure the brain responses evoked by semantic processing in spoken and written word comprehension and production tasks (listening, speaking, reading, and writing). We found that heteromodal word input and output tasks involved distributed brain regions within a frontal-parietal-temporal network and focally coactivated the anterior lateral visual word form area (VWFA), which is located in the basal occipitotemporal area. Directed connectivity analysis revealed that the VWFA was invariably under significant top-down modulation of the frontoparietal control network and interacts with regions related to attention and semantic representation. This study reveals that the VWFA is a key site subserving general semantic processes linking words and meaning, challenging the predominant emphasis on this area's specific role in reading or more general visual processes. Our findings also suggest that the dynamics between semantic memory and cognitive control mechanisms during word processing are largely independent of the modalities of input or output. Binding words and their meaning into a coherent whole during retrieval requires accessing semantic memory and cognitive control, allowing our thoughts to be expressed and comprehended through mind-external tokens in multiple modalities, such as written or spoken forms. However, it is still unknown whether multimodal language comprehension and production share a common word-meaning binding system in human brains and how this system is connected to a cognitive control mechanism. By systematically measuring brain activity evoked by spoken and written verbal input and output tasks tagging word-meaning binding processes, we demonstrate a general word-meaning binding site within the visual word form area (VWFA) and how this site is modulated by the frontal-parietal control network.
人类语言的整体能力和语义记忆驱动了单词及其意义的联系，从理论上讲，这种联系受到认知控制的影响。然而，目前尚不清楚在不同的语言模态和输入/输出格式下，人类大脑中是否存在一个用于单词-意义绑定的共享系统，以及该系统如何与认知控制相互作用。在这里，我们基于一个包含大量受试者（50 名女性，50 名男性）的功能磁共振成像实验，全面测量了口语和书面语理解和产生任务（听、说、读、写）中语义处理所引起的大脑反应。我们发现，异模态单词输入和输出任务涉及到额顶颞叶网络中的分布式脑区，并局部共同激活了位于基底枕颞区的前外侧视觉单词形式区（VWFA）。定向连通性分析表明，VWFA 始终受到额顶控制网络的显著自上而下的调制，并与与注意力和语义表示相关的区域相互作用。这项研究揭示了 VWFA 是一个关键的部位，它支持将单词和意义联系起来的一般语义过程，挑战了该区域在阅读或更一般的视觉过程中具有特定作用的主导观点。我们的研究结果还表明，在单词处理过程中，语义记忆和认知控制机制之间的动态在很大程度上独立于输入或输出的模态。在检索过程中将单词及其意义绑定成一个连贯的整体需要访问语义记忆和认知控制，从而使我们的思想能够通过多种模态（如书面或口头形式）表达和理解。然而，目前尚不清楚人类大脑中多模态语言理解和产生是否共享一个共同的单词-意义绑定系统，以及这个系统如何与认知控制机制相连接。通过系统地测量口语和书面言语输入和输出任务引起的大脑活动，我们证明了在视觉单词形式区（VWFA）中存在一个通用的单词-意义绑定部位，以及该部位如何被额顶控制网络所调制。
