Jagiellonian University in Krakow, Poland.
Jagiellonian University in Krakow, Poland.
Brain Res. 2024 Sep 15;1839:149022. doi: 10.1016/j.brainres.2024.149022. Epub 2024 May 25.
Working memory (WM) is a pivotal neural mechanism for cognitive function and ability. Transcranial alternating current stimulation (tACS) was used to improve WM by entraining key brain rhythms. We submitted to meta-analysis 143 effects of tACS on WM performance, found in 42 reports published between 2014 and 2023, encompassing a total of 1386 healthy adults stimulated. The overall effect size of 134 interventions intended to improve WM equaled Hedges' g = 0.076 [0.039, 0.113]. However, after correcting for a significant publication bias this effect size dropped to zero. By contrast, 9 interventions distorting the brain synchronization using antiphase tACS reliably decreased WM performance, with Hedges' g = -0.266, [-0.458, -0.074]. Individuating the targeted frequency band was the only reliable moderator. The disparity between our null outcome and moderately positive tACS effects estimated by previous meta-analyses resulted from our inclusion of the most recent studies mostly reporting negligible effects. Our results suggest that current tACS protocols barely enhance WM in healthy adults. More research is needed to develop effective methods for WM stimulation.
工作记忆（WM）是认知功能和能力的关键神经机制。经颅交流电刺激（tACS）通过对关键脑节律进行调制来改善 WM。我们对 2014 年至 2023 年间发表的 42 份报告中的 143 项 tACS 对 WM 表现影响的效应进行了荟萃分析，这些报告共涉及 1386 名接受刺激的健康成年人。旨在改善 WM 的 134 项干预措施的总体效应大小等于 Hedges' g = 0.076 [0.039, 0.113]。然而，在纠正了显著的发表偏倚后，该效应大小降为零。相比之下，使用反相 tACS 干扰大脑同步的 9 项干预措施可靠地降低了 WM 表现，Hedges' g = -0.266，[-0.458, -0.074]。区分目标频带是唯一可靠的调节因素。我们的零结果与之前荟萃分析中估计的适度正 tACS 效应之间的差异，源于我们纳入了最近的研究，这些研究大多报告的效果微不足道。我们的研究结果表明，当前的 tACS 方案几乎不能增强健康成年人的 WM。需要进一步研究来开发 WM 刺激的有效方法。
