Savic Branislav, Müri René, Meier Beat
Institute of Psychology and Center for Cognition, Learning, and Memory, University of Bern, Switzerland.
Department of Neurology, Bern University Hospital Inselspital, and Center for Cognition, Learning, and Memory, University of Bern, Bern, Switzerland.
Brain Stimul. 2017 May-Jun;10(3):567-575. doi: 10.1016/j.brs.2017.01.001. Epub 2017 Jan 4.
Transcranial direct current stimulation (tDCS) is assumed to affect cortical excitability and dependent on the specific stimulation conditions either to increase or decrease learning.
The purpose of this study was to modulate implicit task sequence learning with tDCS.
As cortico-striatal loops are critically involved in implicit task sequence learning, tDCS was applied above the dorsolateral prefrontal cortex (DLPFC). In Experiment 1, anodal, cathodal, or sham tDCS was applied before the start of the sequence learning task. In Experiment 2, stimulation was applied during the sequence learning task. Consolidation of learning was assessed after 24 h.
The results of both experiments showed that implicit task sequence learning occurred consistently but it was not modulated by different tDCS conditions. Similarly, consolidation measured after a 24 h-interval including sleep was also not affected by stimulation.
These results indicate that a single session of DLPFC tDCS is not sufficient to modulate implicit task sequence learning. This study adds to the accumulating evidence that tDCS may not be as effective as originally thought.
经颅直流电刺激（tDCS）被认为会影响皮层兴奋性，并取决于特定的刺激条件，从而增加或减少学习能力。
本研究旨在用tDCS调节内隐任务序列学习。
由于皮质-纹状体环路在很大程度上参与内隐任务序列学习，因此tDCS应用于背外侧前额叶皮层（DLPFC）上方。在实验1中，在序列学习任务开始前施加阳极、阴极或假tDCS。在实验2中，在序列学习任务期间施加刺激。24小时后评估学习巩固情况。
两个实验的结果均表明，内隐任务序列学习持续发生，但不受不同tDCS条件的调节。同样，包括睡眠在内的24小时间隔后测量的巩固情况也不受刺激影响。
这些结果表明，单次DLPFC tDCS不足以调节内隐任务序列学习。这项研究进一步证明了tDCS可能不像最初认为的那样有效。
