tACS Phase Locking of Frontal Midline Theta Oscillations Disrupts Working Memory Performance.
tACS Phase Locking of Frontal Midline Theta Oscillations Disrupts Working Memory Performance.
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DOI：
10.3389/fncel.2016.00120
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发表时间：
2016
影响因子：
5.3
通讯作者：
Soekadar SR
中科院分区：
文献类型：
--
作者：
Chander BS;Witkowski M;Braun C;Robinson SE;Born J;Cohen LG;Birbaumer N;Soekadar SR
工作背景：额叶中线theta（FMT）振荡（4-8 Hz）与记忆处理、算术问题解决或持续注意力等心理任务期间的认知和执行控制密切相关。虽然在工作记忆（WM）任务中的时间顺序信息的维护最近被链接到FMT阶段，FMT功率，WM需求和WM性能之间的正相关关系。然而，这些措施之间的关系还没有得到很好的理解，它是未知的，是否有目的的FMT相位操纵WM任务期间的影响FMT功率和WM性能。在这里，我们提出的证据表明，经颅交流电刺激（tACS）介导的FMT相位操纵可以阻止WM需求相关的FMT功率增加（FMTΔ功率），并破坏正常的WM性能。研究方法：将20名健康志愿者分为两组（A组、B组），分别在基线区（区1）和干预区（区2）进行2-back任务，同时记录275探头脑磁图（MEG）。在块1期间不施加刺激后，A组中的参与者在前额叶皮层（PFC）上以其个人FMT频率接受tACS振荡，而B组在块2期间接受假刺激。在评估和映射tACS信号和整个大脑的脑振荡活动之间的锁相值（PLV）后，评估FMT功率和WM性能，并在块和组之间进行比较。结果如下：在A组而非B组的阻滞2期间，FMT振荡显示在额叶tACS电极下方的任务相关皮层区域中PLV增加。虽然在第1组中，WM任务相关的FMTΔ功率和WM性能在各组之间相当，但在第2组中，与假刺激相比，tACS导致FMTΔ功率和WM性能较低。结论：tACS相关的FMT时相操作可干扰WM的执行，影响WM任务相关的FMTΔ功率。这一发现可能对治疗脑疾病具有重要意义，例如与FMT活性的异常调节相关的抑郁症和注意力缺陷障碍，或以脑活动的功能障碍性耦合为特征的疾病，例如，癫痫、阿尔茨海默病或帕金森病（AD/PD）。
Background: Frontal midline theta (FMT) oscillations (4–8 Hz) are strongly related to cognitive and executive control during mental tasks such as memory processing, arithmetic problem solving or sustained attention. While maintenance of temporal order information during a working memory (WM) task was recently linked to FMT phase, a positive correlation between FMT power, WM demand and WM performance was shown. However, the relationship between these measures is not well understood, and it is unknown whether purposeful FMT phase manipulation during a WM task impacts FMT power and WM performance. Here we present evidence that FMT phase manipulation mediated by transcranial alternating current stimulation (tACS) can block WM demand-related FMT power increase (FMTΔpower) and disrupt normal WM performance. Methods: Twenty healthy volunteers were assigned to one of two groups (group A, group B) and performed a 2-back task across a baseline block (block 1) and an intervention block (block 2) while 275-sensor magnetoencephalography (MEG) was recorded. After no stimulation was applied during block 1, participants in group A received tACS oscillating at their individual FMT frequency over the prefrontal cortex (PFC) while group B received sham stimulation during block 2. After assessing and mapping phase locking values (PLV) between the tACS signal and brain oscillatory activity across the whole brain, FMT power and WM performance were assessed and compared between blocks and groups. Results: During block 2 of group A but not B, FMT oscillations showed increased PLV across task-related cortical areas underneath the frontal tACS electrode. While WM task-related FMTΔpower and WM performance were comparable across groups in block 1, tACS resulted in lower FMTΔpower and WM performance compared to sham stimulation in block 2. Conclusion: tACS-related manipulation of FMT phase can disrupt WM performance and influence WM task-related FMTΔpower. This finding may have important implications for the treatment of brain disorders such as depression and attention deficit disorder associated with abnormal regulation of FMT activity or disorders characterized by dysfunctional coupling of brain activity, e.g., epilepsy, Alzheimer’s or Parkinson’s disease (AD/PD).