Zhang Qiushi, Zhang Gaoyan, Yao Li, Zhao Xiaojie
College of Information Science and Technology, Beijing Normal University Beijing, China.
School of Computer Science and Technology, Tianjin University Tianjin, China.
Front Behav Neurosci. 2015 Sep 4;9:244. doi: 10.3389/fnbeh.2015.00244. eCollection 2015.
Working memory (WM) refers to the temporary holding and manipulation of information during the performance of a range of cognitive tasks, and WM training is a promising method for improving an individual's cognitive functions. Our previous work demonstrated that WM performance can be improved through self-regulation of dorsal lateral prefrontal cortex (PFC) activation using real-time functional magnetic resonance imaging (rtfMRI), which enables individuals to control local brain activities volitionally according to the neurofeedback. Furthermore, research concerning large-scale brain networks has demonstrated that WM training requires the engagement of several networks, including the central executive network (CEN), the default mode network (DMN) and the salience network (SN), and functional connectivity within the CEN and DMN can be changed by WM training. Although a switching role of the SN between the CEN and DMN has been demonstrated, it remains unclear whether WM training can affect the interactions between the three networks and whether a similar mechanism also exists during the training process. In this study, we investigated the dynamic functional connectivity between the three networks during the rtfMRI feedback training using independent component analysis (ICA) and correlation analysis. The results indicated that functional connectivity within and between the three networks were significantly enhanced by feedback training, and most of the changes were associated with the insula and correlated with behavioral improvements. These findings suggest that the insula plays a critical role in the reorganization of functional connectivity among the three networks induced by rtfMRI training and in WM performance, thus providing new insights into the mechanisms of high-level functions and the clinical treatment of related functional impairments.
工作记忆（WM）是指在执行一系列认知任务期间对信息的临时存储和处理，而工作记忆训练是改善个体认知功能的一种很有前景的方法。我们之前的研究表明，通过使用实时功能磁共振成像（rtfMRI）对背外侧前额叶皮层（PFC）激活进行自我调节，可以提高工作记忆表现，这使个体能够根据神经反馈自主控制局部脑活动。此外，有关大规模脑网络的研究表明，工作记忆训练需要多个网络的参与，包括中央执行网络（CEN）、默认模式网络（DMN）和突显网络（SN），并且工作记忆训练可以改变CEN和DMN内的功能连接。尽管已经证明了SN在CEN和DMN之间的切换作用，但工作记忆训练是否会影响这三个网络之间的相互作用，以及在训练过程中是否也存在类似机制仍不清楚。在本研究中，我们使用独立成分分析（ICA）和相关性分析，研究了rtfMRI反馈训练期间这三个网络之间的动态功能连接。结果表明，反馈训练显著增强了这三个网络内部以及它们之间的功能连接，并且大多数变化与脑岛有关，并且与行为改善相关。这些发现表明，脑岛在rtfMRI训练诱导的三个网络之间的功能连接重组以及工作记忆表现中起着关键作用，从而为高级功能机制和相关功能障碍的临床治疗提供了新的见解。
