Menze Inga, Mueller Notger G, Zaehle Tino, Schmicker Marlen
German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany.
Research Group Degenerative and Chronic Diseases, Movement, Faculty of Health Sciences Brandenburg, University of Potsdam, Potsdam, Germany.
Front Hum Neurosci. 2023 Mar 9;17:1134632. doi: 10.3389/fnhum.2023.1134632. eCollection 2023.
Attempts to improve cognitive abilities via transcranial direct current stimulation (tDCS) have led to ambiguous results, likely due to the method's susceptibility to methodological and inter-individual factors. Conventional tDCS, i.e., using an active electrode over brain areas associated with the targeted cognitive function and a supposedly passive reference, neglects stimulation effects on entire neural networks.
We investigated the advantage of frontoparietal network stimulation (right prefrontal anode, left posterior parietal cathode) against conventional and sham tDCS in modulating working memory (WM) capacity dependent transfer effects of a single-session distractor inhibition (DIIN) training. Since previous results did not clarify whether electrode montage drives this individual transfer, we here compared conventional to frontoparietal and sham tDCS and reanalyzed data of 124 young, healthy participants in a more robust way using linear mixed effect modeling.
The interaction of electrode montage and WM capacity resulted in systematic differences in transfer effects. While higher performance gains were observed with increasing WM capacity in the frontoparietal stimulation group, low WM capacity individuals benefited more in the sham condition. The conventional stimulation group showed subtle performance gains independent of WM capacity.
Our results confirm our previous findings of WM capacity dependent transfer effects on WM by a single-session DIIN training combined with tDCS and additionally highlight the pivotal role of the specific electrode montage. WM capacity dependent differences in frontoparietal network recruitment, especially regarding the parietal involvement, are assumed to underlie this observation.
通过经颅直流电刺激（tDCS）来提高认知能力的尝试产生了不明确的结果，这可能是由于该方法易受方法学和个体间因素的影响。传统的tDCS，即在与目标认知功能相关的脑区上方使用一个有源电极和一个假定为无源的参考电极，忽略了对整个神经网络的刺激作用。
我们研究了额顶叶网络刺激（右前额阳极，左后顶叶阴极）相对于传统和假tDCS在调节单节分心抑制（DIIN）训练的工作记忆（WM）容量依赖性转移效应方面的优势。由于先前的结果并未阐明电极组合是否驱动这种个体转移，我们在此比较了传统刺激、额顶叶刺激和假tDCS，并使用线性混合效应模型以更稳健的方式重新分析了124名年轻健康参与者的数据。
电极组合与WM容量的相互作用导致了转移效应的系统性差异。虽然在前额顶叶刺激组中，随着WM容量的增加观察到更高的性能提升，但低WM容量个体在假刺激条件下受益更多。传统刺激组显示出与WM容量无关的细微性能提升。
我们的结果证实了我们之前的发现，即单节DIIN训练结合tDCS对WM具有WM容量依赖性转移效应，并且还突出了特定电极组合的关键作用。前额顶叶网络募集的WM容量依赖性差异，特别是关于顶叶的参与，被认为是这一观察结果的基础。
