Dynamics within and between functional resting‐state networks have a crucial role in determining both healthy and pathological brain functioning in humans. The possibility to noninvasively interact and selectively modulate the activity of networks would open to relevant applications in neuroscience. Here we tested a novel approach for multichannel, network‐targeted transcranial direct current stimulation (net‐tDCS), optimized to increase excitability of the sensorimotor network (SMN) while inducing cathodal inhibitory modulation over prefrontal and parietal brain regions negatively correlated with the SMN. Using an MRI‐compatible multichannel transcranial electrical stimulation (tES) device, 20 healthy participants underwent real and sham tDCS while at rest in the MRI scanner. Changes in functional connectivity (FC) during and after stimulation were evaluated, looking at the intrinsic FC of the SMN and the strength of the negative connectivity between SMN and the rest of the brain. Standard, bifocal tDCS targeting left motor cortex (electrode ~C3) and right frontopolar (~Fp2) regions was tested as a control condition in a separate sample of healthy subjects to investigate network specificity of multichannel stimulation effects. Net‐tDCS induced greater FC increase over the SMN compared to bifocal tDCS, during and after stimulation. Moreover, exploratory analysis of the impact of net‐tDCS on negatively correlated networks showed an increase in the negative connectivity between SMN and prefrontal/parietal areas targeted by cathodal stimulation both during and after real net‐tDCS. Results suggest preliminary evidence of the possibility of manipulating distributed network connectivity patterns through net‐tDCS, with potential relevance for the development of cognitive enhancement and therapeutic tES solutions.

中文翻译：

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网络靶向多通道经颅直流电刺激对内在和网络间功能连接的影响。

功能性静息状态网络内部和之间的动力学在确定人类健康和病理性大脑功能方面具有至关重要的作用。非侵入性交互和选择性调节网络活动的可能性将对神经科学中的相关应用开放。在这里，我们测试了一种用于多通道、网络靶向经颅直流电刺激 (net-tDCS) 的新方法，该方法经过优化以增加感觉运动网络 (SMN) 的兴奋性，同时诱导与 SMN 负相关的前额叶和顶叶脑区域的阴极抑制调制。使用与 MRI 兼容的多通道经颅电刺激 (tES) 设备，20 名健康参与者在 MRI 扫描仪中休息时接受了真实和假 tDCS。评估刺激期间和之后功能连接 (FC) 的变化，观察 SMN 的内在 FC 以及 SMN 与大脑其他部分之间的负连接强度。针对左运动皮层（电极~C3）和右额极（~Fp2）区域的标准双焦 tDCS 作为对照条件在健康受试者的单独样本中进行了测试，以研究多通道刺激效应的网络特异性。与双焦点 tDCS 相比，在刺激期间和之后，Net-tDCS 在 SMN 上诱导更大的 FC 增加。此外，对 net-tDCS 对负相关网络影响的探索性分析表明，在实际 net-tDCS 期间和之后，SMN 与阴极刺激所针对的前额叶/顶叶区域之间的负连接性增加。