Monash Alfred Psychiatry Research Centre, School of Psychology and Psychiatry, Monash University and The Alfred, Commercial Rd, Melbourne, Victoria, Australia.
Brain Stimul. 2011 Apr;4(2):84-9. doi: 10.1016/j.brs.2010.06.004. Epub 2010 Jul 11.
Transcranial direct current stimulation (tDCS), applied to the left dorsolateral prefrontal cortex (DLPFC) has been found to improve working memory (WM) performance in both healthy and clinical participants. However, whether this effect can be enhanced by cognitive activity undertaken during tDCS has not yet been explored.
This study aimed to explore whether tDCS applied to the left DLPFC during the persistent performance of one WM task would improve performance on a subsequent WM task, to a greater extent than either tDCS or cognitive activity alone.
Ten healthy participants took part in three counterbalanced conditions. The conditions involved 10 minutes of either anodal tDCS while completing an n-back task, anodal tDCS while at rest, or sham tDCS while completing an n-back task. The n-back that was used in this study was a computer-based letter WM task that involved 5 minutes of two-back, followed by 5 minutes of three-back. Digit span forward and backward was administered immediately before and after each treatment, and performance change (pre- to posttreatment) calculated and compared across conditions. The digit span tasks involved a series of numbers being read to the participant, and the participant was required to repeat them back, either in the same order (Digits forward) or in the reverse order (Digits backward).
tDCS applied during completion of the n-back task was found to result in greater improvement in performance on digit span forward, compared with tDCS applied while at rest and sham tDCS during the n-back task. This finding was not evident with digit span backward.
These results indicate that there may be potential for the use of adjunctive cognitive remediation techniques to enhance the effects of tDCS. However, further research needs to be undertaken in this area to replicate and extend this finding.
经颅直流电刺激（tDCS）作用于左侧背外侧前额叶皮层（DLPFC）已被发现可改善健康和临床参与者的工作记忆（WM）表现。然而，在 tDCS 期间进行认知活动是否可以增强这种效果尚未得到探索。
本研究旨在探讨在持续进行一项 WM 任务期间将 tDCS 施加于左侧 DLPFC 是否会比单独进行 tDCS 或认知活动更能提高随后 WM 任务的表现。
10 名健康参与者参与了三个平衡条件。这些条件包括在完成 n-回任务时接受 10 分钟的阳极 tDCS、在休息时接受阳极 tDCS 或在完成 n-回任务时接受假 tDCS。本研究中使用的 n-回是一种基于计算机的字母 WM 任务，包括 5 分钟的两回，然后是 5 分钟的三回。数字跨度前向和后向在每次治疗前后立即进行，计算并比较各条件下的表现变化（治疗前到治疗后）。数字跨度任务涉及一系列数字被读给参与者，参与者需要按照相同的顺序（数字前向）或相反的顺序（数字后向）重复它们。
与在休息时接受 tDCS 和在 n-回任务期间接受假 tDCS相比，在完成 n-回任务时施加 tDCS 被发现可导致数字跨度前向表现的更大改善。这一发现与数字跨度后向无关。
这些结果表明，可能有潜力利用附加认知矫正技术来增强 tDCS 的效果。然而，需要在这一领域进行进一步的研究，以复制和扩展这一发现。
