Bagattini Chiara, Cid-Fernández Susana, Bulgari Martina, Miniussi Carlo, Bortoletto Marta
Neurophysiology Lab, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy.
Section of Neurosurgery, Department of Neuroscience Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
Front Aging Neurosci. 2023 Jan 25;15:1087749. doi: 10.3389/fnagi.2023.1087749. eCollection 2023.
Episodic memory (EM) exhibits an age-related decline, with overall increased impairment after the age of 65. The application of transcranial direct current stimulation (tDCS) to ameliorate cognitive decline in ageing has been extensively investigated, but its efficacy has been reported with mixed results. In this study, we aimed to assess whether age contributes to interindividual variability in tDCS efficacy.
Thirty-eight healthy adults between 50 and 81 years old received anodal tDCS over the left prefrontal cortex during images encoding and then performed an EM recognition task while event-related potentials (ERPs) were recorded.
Our results showed an opposite pattern of effect between middle-aged (50-64 years) and older (65-81 years) adults. Specifically, performance in the recognition task after tDCS was enhanced in older adults and was worsened in middle-aged adults. Moreover, ERPs acquired during the recognition task showed that two EM components related to familiarity and post-retrieval monitoring, i.e., Early Frontal and Late Frontal Old-New effects, respectively, were significantly reduced in middle-aged adults after anodal tDCS.
These results support an age-dependent effect of prefrontal tDCS on EM processes and its underlying electrophysiological substrate, with opposing modulatory trajectories along the aging lifespan.
情景记忆（EM）呈现出与年龄相关的衰退，65岁之后总体损伤加剧。经颅直流电刺激（tDCS）应用于改善衰老过程中的认知衰退已得到广泛研究，但其疗效报道不一。在本研究中，我们旨在评估年龄是否会导致tDCS疗效的个体间差异。
38名年龄在50至81岁之间的健康成年人在图像编码期间接受左侧前额叶皮层阳极tDCS，然后在记录事件相关电位（ERP）的同时执行EM识别任务。
我们的结果显示中年（50 - 64岁）和老年（65 - 81岁）成年人之间存在相反的效应模式。具体而言，tDCS后老年成年人的识别任务表现得到增强，而中年成年人的表现则变差。此外，在识别任务期间获取的ERP显示，阳极tDCS后中年成年人中与熟悉度和检索后监测相关的两个EM成分，即早期额叶和晚期额叶新旧效应，分别显著降低。
这些结果支持前额叶tDCS对EM过程及其潜在电生理底物的年龄依赖性效应，在衰老过程中具有相反的调节轨迹。
