Callan Daniel E, Falcone Brian, Wada Atsushi, Parasuraman Raja
Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology (NICT), Osaka UniversityOsaka, Japan; Multisensory Cognition and Computation Laboratory, Universal Communication Research Institute, National Institute of Information and Communications TechnologyKyoto, Japan.
Center of Excellence in Neuroergonomics, Technology, and Cognition (CENTEC), George Mason University Fairfax, VA, USA.
Front Hum Neurosci. 2016 Mar 7;10:72. doi: 10.3389/fnhum.2016.00072. eCollection 2016.
This study uses simultaneous transcranial direct current stimulation (tDCS) and functional MRI (fMRI) to investigate tDCS modulation of resting state activity and connectivity that underlies enhancement in behavioral performance. The experiment consisted of three sessions within the fMRI scanner in which participants conducted a visual search task: Session 1: Pre-training (no performance feedback), Session 2: Training (performance feedback given), Session 3: Post-training (no performance feedback). Resting state activity was recorded during the last 5 min of each session. During the 2nd session one group of participants underwent 1 mA tDCS stimulation and another underwent sham stimulation over the right posterior parietal cortex. Resting state spontaneous activity, as measured by fractional amplitude of low frequency fluctuations (fALFF), for session 2 showed significant differences between the tDCS stim and sham groups in the precuneus. Resting state functional connectivity from the precuneus to the substantia nigra, a subcortical dopaminergic region, was found to correlate with future improvement in visual search task performance for the stim over the sham group during active stimulation in session 2. The after-effect of stimulation on resting state functional connectivity was measured following a post-training experimental session (session 3). The left cerebellum Lobule VIIa Crus I showed performance related enhancement in resting state functional connectivity for the tDCS stim over the sham group. The ability to determine the relationship that the relative strength of resting state functional connectivity for an individual undergoing tDCS has on future enhancement in behavioral performance has wide ranging implications for neuroergonomic as well as therapeutic, and rehabilitative applications.
本研究采用同步经颅直流电刺激（tDCS）和功能磁共振成像（fMRI）来研究tDCS对静息状态活动和连接性的调节作用，这些活动和连接性是行为表现增强的基础。实验在fMRI扫描仪内进行，包括三个阶段，参与者在其中执行视觉搜索任务：阶段1：预训练（无表现反馈），阶段2：训练（给予表现反馈），阶段3：训练后（无表现反馈）。在每个阶段的最后5分钟记录静息状态活动。在第二阶段，一组参与者在右后顶叶皮层接受1 mA的tDCS刺激，另一组接受假刺激。通过低频波动分数振幅（fALFF）测量的第二阶段静息状态自发活动显示，tDCS刺激组和假刺激组在楔前叶存在显著差异。发现从楔前叶到黑质（一个皮层下多巴胺能区域）的静息状态功能连接与第二阶段主动刺激期间tDCS刺激组相对于假刺激组在视觉搜索任务表现上的未来改善相关。在训练后实验阶段（第三阶段）之后测量刺激对静息状态功能连接的后效应。与假刺激组相比，左侧小脑小叶VIIa Crus I在tDCS刺激组的静息状态功能连接中表现出与表现相关的增强。确定接受tDCS的个体的静息状态功能连接的相对强度与未来行为表现增强之间的关系的能力，对神经工效学以及治疗和康复应用具有广泛的意义。
