Xie Yuanjun, Li Yanyan, Duan Haidan, Xu Xiliang, Zhang Wenmo, Fang Peng
School of Education, Xin Yang College, Xinyang, China.
Department of Radiology, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
Front Hum Neurosci. 2021 Mar 8;15:614950. doi: 10.3389/fnhum.2021.614950. eCollection 2021.
Working memory is a limited capacity memory system that involves the short-term storage and processing of information. Neuroscientific studies of working memory have mostly focused on the essential roles of neural oscillations during item encoding from single sensory modalities (e.g., visual and auditory). However, the characteristics of neural oscillations during multisensory encoding in working memory are rarely studied. Our study investigated the oscillation characteristics of neural signals in scalp electrodes and mapped functional brain connectivity while participants encoded complex audiovisual objects in a working memory task. Experimental results showed that theta oscillations (4-8 Hz) were prominent and topographically distributed across multiple cortical regions, including prefrontal (e.g., superior frontal gyrus), parietal (e.g., precuneus), temporal (e.g., inferior temporal gyrus), and occipital (e.g., cuneus) cortices. Furthermore, neural connectivity at the theta oscillation frequency was significant in these cortical regions during audiovisual object encoding compared with single modality object encoding. These results suggest that local oscillations and interregional connectivity theta activity play an important role during audiovisual object encoding and may contribute to the formation of working memory traces from multisensory items.
工作记忆是一种容量有限的记忆系统，涉及信息的短期存储和处理。工作记忆的神经科学研究大多集中在单一感觉模态（如视觉和听觉）的项目编码过程中神经振荡的重要作用。然而，工作记忆中多感觉编码过程中的神经振荡特征很少被研究。我们的研究调查了头皮电极中神经信号的振荡特征，并绘制了功能性脑连接图谱，同时参与者在工作记忆任务中对复杂的视听对象进行编码。实验结果表明，θ振荡（4 - 8赫兹）很突出，并且在多个皮质区域呈拓扑分布，包括前额叶（如额上回）、顶叶（如楔前叶）、颞叶（如下颞叶）和枕叶（如楔叶）皮质。此外，与单模态对象编码相比，在视听对象编码过程中，这些皮质区域在θ振荡频率下的神经连接是显著的。这些结果表明，局部振荡和区域间连接的θ活动在视听对象编码过程中起重要作用，并且可能有助于多感觉项目工作记忆痕迹的形成。
