脑网络经颅直流电刺激对老年人工作记忆的影响

关键词：经颅直流电刺激  老年人  工作记忆  认知  脑网络

Keywords:transcranial direct current stimulation  older adults  working memory  cognition  brain network

摘要：

      摘要 目的：探究基于脑网络的经颅直流电刺激（transcranial direct current stimulation，tDCS）对老年人工作记忆的影响。 方法：采用双盲、随机交叉对照的试验设计。健康老年人随机接受tDCS和假刺激，两次刺激间隔至少1周。tDCS方案旨在促进DAN的兴奋性并抑制DN的兴奋性，刺激时长为20min；假刺激方案仅持续1min（刺激开始和结束各30s）。使用N-back任务评估工作记忆表现，主要结局指标为d-prime分数及反应时。通过双因素重复测量方差分析观察刺激方式对工作记忆的影响。 结果：28例受试者完成了试验且未出现明显的不良反应。结果显示1-back任务的d-prime分数（F=4.288， P=0.043，η2p=0.074）及反应时（F=5.836， P=0.019， η2p=0.098）存在显著交互效应。事后分析发现，受试者接受tDCS后1-back的d-prime分数显著提高（P=0.012），反应时显著降低（P<0.001）。 结论：基于脑网络的tDCS能够显著改善老年人的工作记忆表现，为老年认知功能的非药物干预提供了新思路。

Abstract:

      Abstract Objective： To investigate the effect of network-based transcranial direct current stimulation （tDCS） based on specific brain networks on the working memory of older adults. Method： The study was a double-blind， randomized， crossover design. Healthy older adults were randomly assigned to receive either tDCS or sham stimulation， with a minimum one-week interval between stimulation. The tDCS protocol aimed to enhance DAN excitability while inhibiting DN excitability， with a stimulation duration of 20 minutes. Sham stimulation lasted only 1 minute （30 seconds each at the beginning and the end of stimulation）. Working memory performance was evaluated using the N-back task. Primary outcome measures included d-prime scores and reaction times. A two-way repeated-measures analysis of variance was conducted to assess the impact of stimulation on working memory. Result： Twenty-eight participants completed the experiment， with no significant side effects reported. Analysis revealed significant interaction effects for the d-prime scores（F=4.288，P=0.043，η2p=0.074） and the reaction times（F=5.836，P=0.019，η2p=0.098） in the 1-back task. Post-hoc analysis demonstrated the significant enhancements in the d-prime scores（P=0.012） and significant reductions in the reaction times（P<0.001） for the 1-back task following tDCS. Conclusion： Network-based tDCS significantly enhances working memory performance in older adults， and presents a promising avenue for non-pharmacological interventions in age-related cognitive decline.