Modulation of frontal effective connectivity during speech.
Modulation of frontal effective connectivity during speech.
复制标题
DOI：
10.1016/j.neuroimage.2016.01.037
复制
发表时间：
2016-10-15
期刊：
影响因子：
5.7
通讯作者：
Crinion J
中科院分区：
文献类型：
--
作者：
Holland R;Leff AP;Penny WD;Rothwell JC;Crinion J
非侵入性神经刺激方法，如经颅直流电刺激（tDCS）可以引起新皮层兴奋性的持久、极性依赖的变化。在之前的一项同时进行的tDCS- fmri研究中，我们报道了将阳极tDCS应用于左额叶皮层时，在左额叶下皮质（IFC）中显著的行为和区域特异性神经促进作用（Holland等，2011）。尽管在静态状态下模拟了阳极tDCS的分布式连接效应，但“在线”tDCS在任务状态下调节神经元连接的机制尚不清楚。在这里，我们使用动态因果模型（DCM）来确定：(i)在阳极tDCS期间，额叶语音网络中的神经连接是如何被调制的；（ii）个体对阳极tDCS的行为反应差异如何与有效连接强度的变化相关。结果表明，与假手术相比，阳极tDCS诱导额下沟（IFS）向腹侧运动前区（VPM）的反馈更强，且VPM内的自我连接更弱，与神经元适应过程一致。在节点tDCS过程中，从IFS到VPM的前馈连接强度的个体变异与命名行为的促进程度呈正相关。这些结果为理解“在线”tDCS与认知任务配对的机制提供了重要的一步。他们还认为，左翼IFS是一个“自上而下”的中心，是语言变革的驱动力。
Noninvasive neurostimulation methods such as transcranial direct current stimulation (tDCS) can elicit long-lasting, polarity-dependent changes in neocortical excitability. In a previous concurrent tDCS-fMRI study of overt picture naming, we reported significant behavioural and regionally specific neural facilitation effects in left inferior frontal cortex (IFC) with anodal tDCS applied to left frontal cortex (Holland et al., 2011). Although distributed connectivity effects of anodal tDCS have been modelled at rest, the mechanism by which ‘on-line’ tDCS may modulate neuronal connectivity during a task-state remains unclear. Here, we used Dynamic Causal Modelling (DCM) to determine: (i) how neural connectivity within the frontal speech network is modulated during anodal tDCS; and, (ii) how individual variability in behavioural response to anodal tDCS relates to changes in effective connectivity strength. Results showed that compared to sham, anodal tDCS elicited stronger feedback from inferior frontal sulcus (IFS) to ventral premotor (VPM) accompanied by weaker self-connections within VPM, consistent with processes of neuronal adaptation. During anodal tDCS individual variability in the feedforward connection strength from IFS to VPM positively correlated with the degree of facilitation in naming behaviour. These results provide an essential step towards understanding the mechanism of ‘online’ tDCS paired with a cognitive task. They also identify left IFS as a ‘top-down’ hub and driver for speech change.
登录
查看更多内容
影响因子：
16.2
作者：
Bosman CA;Schoffelen JM;Brunet N;Oostenveld R;Bastos AM;Womelsdorf T;Rubehn B;Stieglitz T;De Weerd P;Fries P
通讯作者：
Fries P
影响因子：
16.2
作者：
Koster-Hale J;Saxe R
通讯作者：
Saxe R
影响因子：
4.3
作者：
Friston K
通讯作者：
Friston K
影响因子：
56.9
作者：
Büchel, C;Coull, JT;Friston, KJ
通讯作者：
Friston, KJ
影响因子：
1.7
作者：
Antal, A;Varga, ET;Paulus, W
通讯作者：
Paulus, W