Bartl Gergely, Allen Paul, Sandrini Marco
Division of Psychiatry, Faculty of Brain Sciences, University College London, London W1T 7BN, UK.
School of Psychology, University of Roehampton, London SW15 4JD, UK.
Brain Sci. 2023 Jan 31;13(2):241. doi: 10.3390/brainsci13020241.
Recent studies suggest that transcranial direct current stimulation (tDCS) applied over the prefrontal cortex (PFaC) may enhance episodic memory ability. As such, there is ongoing interest in the therapeutic potential of this technique in age-related memory decline. At the same time, the findings are not yet conclusive regarding the magnitude of this effect, and assumptions regarding underlying brain mechanisms of stimulation-induced changes in behaviour are yet to be tested in detail. Here, we evaluated the effect of tDCS over left PFC on verbal episodic memory in young adults. Two separate randomized, double-blind, sham-controlled experiments were carried out using (1) incidental learning followed by a recognition test and (2) intentional learning followed by a free recall. In both studies, participants performed a learning task with active or sham tDCS during the encoding period, followed by retrieval tasks on the same day and the next day. The results suggest that, contrary to expectations, active tDCS did not enhance memory performance relative to sham tDCS. Possible reasons behind the lack of enhancement effects are discussed, including the possibility that memory enhancement effects of tDCS may be smaller than first thought. Scientific practices that could improve estimation accuracy in the field are also discussed.
最近的研究表明，经颅直流电刺激（tDCS）作用于前额叶皮质（PFaC）可能会增强情景记忆能力。因此，人们对该技术在与年龄相关的记忆衰退方面的治疗潜力持续感兴趣。与此同时，关于这种效应的程度，研究结果尚未定论，并且关于刺激引起行为变化的潜在脑机制的假设也有待详细检验。在此，我们评估了tDCS作用于左前额叶皮质对年轻人言语情景记忆的影响。我们进行了两项独立的随机、双盲、假刺激对照实验，分别采用（1）附带学习后进行识别测试，以及（2）有意学习后进行自由回忆。在两项研究中，参与者在编码阶段进行学习任务时接受主动或假tDCS刺激，随后在当天和第二天进行检索任务。结果表明，与预期相反，相对于假tDCS，主动tDCS并未提高记忆表现。我们讨论了缺乏增强效应背后的可能原因，包括tDCS的记忆增强效应可能比最初认为的要小这一可能性。我们还讨论了可以提高该领域估计准确性的科学方法。
