Jones Kevin T, Peterson Dwight J, Blacker Kara J, Berryhill Marian E
Department of Psychology, Cognitive and Brain Sciences, University of Nevada, Reno, 1664 North Virginia Street, Mail Stop 296, Reno, NV 89557, United States.
Department of Psychology, Concordia College, 901 8th St.S, Moorhead, MN 56562, United States.
Brain Res. 2017 Jul 15;1667:28-40. doi: 10.1016/j.brainres.2017.05.005. Epub 2017 May 11.
There is considerable interest in maintaining working memory (WM) because it is essential to accomplish most cognitive tasks, and it is correlated with fluid intelligence and ecologically valid measures of daily living. Toward this end, WM training protocols aim to improve WM capacity and extend improvements to unpracticed domains, yet success is limited. One emerging approach is to couple WM training with transcranial direct current stimulation (tDCS). This pairing of WM training with tDCS in longitudinal designs promotes behavioral improvement and evidence of transfer of performance gains to untrained WM tasks. However, the mechanism(s) underlying tDCS-linked training benefits remain unclear. Our goal was to gain purchase on this question by recording high-density EEG before and after a weeklong WM training+tDCS study. Participants completed four sessions of frontoparietal tDCS (active anodal or sham) during which they performed a visuospatial WM change detection task. Participants who received active anodal tDCS demonstrated significant improvement on the WM task, unlike those who received sham stimulation. Importantly, this pattern was mirrored by neural correlates in spectral and phase synchrony analyses of the HD-EEG data. Notably, the behavioral interaction was echoed by interactions in frontal-posterior alpha band power, and theta and low alpha oscillations. These findings indicate that one mechanism by which paired tDCS+WM training operates is to enhance cortical efficiency and connectivity in task-relevant networks.
维持工作记忆(WM)备受关注,因为它对于完成大多数认知任务至关重要,并且与流体智力和日常生活的生态有效测量指标相关。为此,工作记忆训练方案旨在提高工作记忆容量,并将改善扩展到未训练的领域,但成效有限。一种新兴方法是将工作记忆训练与经颅直流电刺激(tDCS)相结合。在纵向设计中将工作记忆训练与tDCS配对可促进行为改善,并能证明将表现提升转移到未训练的工作记忆任务中。然而,tDCS相关训练益处的潜在机制仍不清楚。我们的目标是通过在为期一周的工作记忆训练+tDCS研究前后记录高密度脑电图来解决这个问题。参与者完成了四节额顶叶tDCS(主动阳极或假刺激),在此期间他们执行了视觉空间工作记忆变化检测任务。接受主动阳极tDCS的参与者在工作记忆任务上表现出显著改善,而接受假刺激的参与者则不然。重要的是,这种模式在高密度脑电图数据的频谱和相位同步分析中的神经相关性中得到了反映。值得注意的是,行为上的相互作用在额后α波段功率以及θ和低α振荡的相互作用中得到了呼应。这些发现表明,配对的tDCS+工作记忆训练起作用的一种机制是提高任务相关网络中的皮质效率和连通性。