School of Computer Science and Technology, Changchun University of Science and Technology, Changchun, Jilin, P.R. China.
School of Computer Science, Northeast Electric Power University, Jilin, Jilin, P.R. China.
PLoS One. 2019 Aug 23;14(8):e0221185. doi: 10.1371/journal.pone.0221185. eCollection 2019.
Many neuroimaging and electrophysiology studies have suggested that semantic integration as a high-level cognitive process involves various cortical regions and is modulated by attention. However, the cortical network specific to semantic integration and the modulatory mechanism of attention remain unclear. Here, we designed an fMRI experiment using "bimodal stimulus" to extract information regarding the cortical activation related to the effects of semantic integration with and without attention, and then analyzed the characteristics of the cortical network and the modulating effect of attention on semantic integration. To further investigate the related cortical regions, we constructed a functional brain network for processing attended AV stimuli to evaluate the nodal properties using a graph-based method. The results of the fMRI and graph-based analyses showed that the semantic integration with attention activated the anterior temporal lobe (ATL), temporoparietal junction (TPJ), and frontoparietal cortex, with the ATL showing the highest nodal degree and efficiency; in contrast, semantic integration without attention involved a relatively small cortical network, including the posterior superior temporal gyrus (STG), Heschl's gyrus (HG), and precentral gyrus. These results indicated that semantic integration is a complex cognitive process that occurs not only in the attended condition but also in the unattended condition, and that attention could modulate the distribution of cortical networks related to semantic integration. We suggest that semantic integration with attention is a conscious process and needs a wide cortical network working together, in which the ATL plays the role of a central hub; in contrast, semantic integration without attention is a pre-attentive process and involves a relatively smaller cortical network, in which the HG may play an important role. Our study will provide valuable insights into semantic integration and will be useful for investigations on multisensory integration and attention mechanism at multiple processing stages and levels within the cortical hierarchy.
许多神经影像学和电生理学研究表明，语义整合作为一种高级认知过程，涉及到各种皮质区域，并受到注意力的调节。然而，语义整合的皮质网络和注意力的调节机制仍不清楚。在这里，我们设计了一个 fMRI 实验，使用“双模刺激”来提取与有注意和无注意的语义整合相关的皮质激活信息，然后分析皮质网络的特征和注意力对语义整合的调节作用。为了进一步研究相关的皮质区域，我们构建了一个用于处理注意视听刺激的功能脑网络，使用基于图的方法评估节点性质。fMRI 和基于图的分析结果表明，有注意的语义整合激活了前颞叶（ATL）、颞顶联合区（TPJ）和额顶皮质，其中 ATL 的节点度和效率最高；相比之下，无注意的语义整合涉及到相对较小的皮质网络，包括后上颞叶（STG）、Heschl 回（HG）和中央前回。这些结果表明，语义整合是一个复杂的认知过程，不仅在注意条件下发生，而且在非注意条件下也发生，注意力可以调节与语义整合相关的皮质网络的分布。我们认为，有注意的语义整合是一个有意识的过程，需要一个广泛的皮质网络共同作用，其中 ATL 起着中央枢纽的作用；相比之下，无注意的语义整合是一个前注意的过程，涉及到相对较小的皮质网络，其中 HG 可能起着重要作用。我们的研究将为语义整合提供有价值的见解，并有助于在皮质层次的多个处理阶段和水平上研究多感觉整合和注意力机制。
