The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China.
Sichuan Institute for Brain Science and Brain-Inspired Intelligence, Chengdu, China.
J Neurosci Res. 2023 Jul;101(7):1188-1199. doi: 10.1002/jnr.25183. Epub 2023 Mar 3.
Working memory (WM) is a cognitive function involving emergent properties of theta oscillations and large-scale network interactions. The synchronization of WM task-related networks in the brain enhanced WM performance. However, how these networks regulate WM processing is not well known, and the alteration of the interaction among these networks may play an important role in patients with cognitive dysfunction. In this study, we used simultaneous EEG-fMRI to examine the features of theta oscillations and the functional interactions among activation/deactivation networks during the n-back WM task in patients with idiopathic generalized epilepsy (IGE). The results showed that there was more enhancement of frontal theta power along with WM load increase in IGE, and the theta power was positively correlated with the accuracy of the WM tasks. Moreover, fMRI activations/deactivations correlated with n-back tasks were estimated, and we found that the IGE group had increased and widespread activations in high-load WM tasks, including the frontoparietal activation network and task-related deactivation areas, such as the default mode network and primary visual and auditory networks. In addition, the network connectivity results demonstrated decreased counteraction between the activation network and deactivation network, and the counteraction was correlated with the higher theta power in IGE. These results indicated the important role of the interactions between activation and deactivation networks during the WM process, and the unbalance among them may indicate the pathophysiological mechanism of cognitive dysfunction in generalized epilepsy.
工作记忆（WM）是一种认知功能，涉及到θ振荡和大规模网络相互作用的涌现特性。大脑中与 WM 任务相关的网络的同步增强了 WM 表现。然而，这些网络如何调节 WM 处理过程尚不清楚，这些网络之间相互作用的改变可能在认知功能障碍患者中发挥重要作用。在这项研究中，我们使用同时进行的 EEG-fMRI 来检查特发性全面性癫痫（IGE）患者在 n-back WM 任务期间θ振荡的特征以及激活/去激活网络之间的功能相互作用。结果表明，IGE 患者的额叶θ功率随着 WM 负荷的增加而增强，θ功率与 WM 任务的准确性呈正相关。此外，还估计了与 n-back 任务相关的 fMRI 激活/去激活，我们发现 IGE 组在高负荷 WM 任务中存在更多的激活和广泛的激活，包括额顶叶激活网络以及与任务相关的去激活区域，如默认模式网络和初级视觉和听觉网络。此外，网络连通性结果表明激活网络和去激活网络之间的相互作用减弱，并且这种相互作用与 IGE 中的较高θ功率相关。这些结果表明，在 WM 过程中激活和去激活网络之间的相互作用起着重要作用，它们之间的不平衡可能表明了全面性癫痫中认知功能障碍的病理生理机制。
