Senkowski Daniel, Sobirey Rabea, Haslacher David, Soekadar Surjo R
Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Psychiatry and Neurosciences, Charité Campus Mitte (CCM), Charitéplatz 1, 10117 Berlin, Germany.
Cereb Cortex Commun. 2022 May 7;3(2):tgac018. doi: 10.1093/texcom/tgac018. eCollection 2022.
Working memory (WM) is essential for reasoning, decision-making, and problem solving. Recently, there has been an increasing effort in improving WM through noninvasive brain stimulation (NIBS), especially transcranial direct and alternating current stimulation (tDCS/tACS). Studies suggest that tDCS and tACS can modulate WM performance, but large variability in research approaches hinders the identification of optimal stimulation protocols and interpretation of study results. Moreover, it is unclear whether tDCS and tACS differentially affect WM. Here, we summarize and compare studies examining the effects of tDCS and tACS on WM performance in healthy adults. Following PRISMA-selection criteria, our systematic review resulted in 43 studies (29 tDCS, 11 tACS, 3 both) with a total of 1826 adult participants. For tDCS, only 4 out of 23 single-session studies reported effects on WM, while 7 out of 9 multi-session experiments showed positive effects on WM training. For tACS, 10 out of 14 studies demonstrated effects on WM, which were frequency dependent and robust for frontoparietal stimulation. Our review revealed no reliable effect of single-session tDCS on WM but moderate effects of multi-session tDCS and single-session tACS. We discuss the implications of these findings and future directions in the emerging research field of NIBS and WM.
工作记忆对于推理、决策和解决问题至关重要。最近，通过非侵入性脑刺激（NIBS），特别是经颅直流电刺激和交流电刺激（tDCS/tACS）来改善工作记忆的努力日益增加。研究表明，tDCS和tACS可以调节工作记忆表现，但研究方法的巨大差异阻碍了最佳刺激方案的确定以及研究结果的解释。此外，尚不清楚tDCS和tACS对工作记忆的影响是否存在差异。在此，我们总结并比较了研究tDCS和tACS对健康成年人工作记忆表现影响的研究。遵循PRISMA选择标准，我们的系统综述得出了43项研究（29项tDCS研究、11项tACS研究、3项两者皆有的研究），共有1826名成年参与者。对于tDCS，23项单疗程研究中只有4项报告了对工作记忆的影响，而9项多疗程实验中有7项显示对工作记忆训练有积极影响。对于tACS，14项研究中有10项证明了对工作记忆的影响，这些影响与频率相关，且对额顶叶刺激具有稳健性。我们的综述揭示了单疗程tDCS对工作记忆没有可靠影响，但多疗程tDCS和单疗程tACS有适度影响。我们讨论了这些发现的意义以及在NIBS和工作记忆这一新兴研究领域的未来方向。
