University of Belgrade, Institute for Medical Research, Dr. Subotića 4, P.O. Box 102, 11129, Belgrade, Serbia.
University of Belgrade, Institute for Medical Research, Dr. Subotića 4, P.O. Box 102, 11129, Belgrade, Serbia; University of Belgrade, Faculty of Philosophy, Department of Psychology, Čika Ljubina 18-20, 11000, Belgrade, Serbia.
Behav Brain Res. 2019 Jul 2;366:88-95. doi: 10.1016/j.bbr.2019.03.023. Epub 2019 Mar 14.
Associative memory (AM), an ability to form and retrieve associations between information units is crucial for everyday functioning and is affected by aging as well as by different neurological conditions. It was shown that rTMS over posterior parietal cortex (PPC) can improve AM of face-word pairs. Therefore, we examined if tDCS will produce comparable effects and explore whether the effect would persist one and five days following the stimulation. Thirty-seven healthy participants took part in cross-over sham-controlled study in which they received 20 min of anodal (1.5 mA) or sham tDCS over left PPC. Following tDCS participants completed face-cued word recall and verbal fluency tasks. A randomly selected subsample (N = 18) has completed follow up memory assessments one and five days after the stimulation. Anodal tDCS facilitated AM performance in comparison to sham with the same trend persisting during the 5-day follow-up period. Additionally, participants with lower AM scores had higher relative gain following anodal tDCS. Anodal tDCS had no effect on the control task (verbal fluency). Results support the existence of a specific enhancing effect on AM produced by facilitatory neuromodulation of the PPC. The effect was more prominent in low-performers and it persisted at least 5 days post-stimulation. These findings support the robustness of tDCS effect on AM and provide a foundation for future research that could lead to its future clinical application.
联想记忆（AM），即形成和提取信息单元之间关联的能力，对日常功能至关重要，并且会受到衰老和不同神经状况的影响。研究表明，经颅磁刺激（rTMS）后顶叶皮层（PPC）可改善面孔-单词对的 AM。因此，我们研究了经颅直流电刺激（tDCS）是否会产生类似的效果，并探讨了刺激后一天和五天的效果是否会持续。37 名健康参与者参加了交叉假对照研究，他们接受了左 PPC 上 20 分钟的阳极（1.5 mA）或假 tDCS。tDCS 后，参与者完成面孔提示单词回忆和言语流畅性任务。随机选择的亚样本（N=18）在刺激后一天和五天完成了后续记忆评估。与假刺激相比，阳极 tDCS 促进了 AM 表现，这种趋势在五天的随访期间持续存在。此外，AM 得分较低的参与者在接受阳极 tDCS 后获得了更高的相对增益。阳极 tDCS 对控制任务（言语流畅性）没有影响。结果支持 PPC 促进神经调节对 AM 产生特定增强作用的存在。该效果在表现较差的参与者中更为明显，并且至少在刺激后五天持续存在。这些发现支持 tDCS 对 AM 的效果的稳健性，并为未来可能导致其临床应用的研究提供了基础。
