Department of Psychology, Kingston University, Penrhyn Road, Kingston Upon Thames, Surrey, UK.
Institute of Cognitive Neuroscience, University College London, London, UK.
Cereb Cortex. 2019 Feb 1;29(2):657-665. doi: 10.1093/cercor/bhx347.
In the past decade, several studies have investigated the effects of transcranial direct current stimulation (tDCS) on episodic memory abilities. However, the specific conditions under which tDCS affects memory remain largely unclear. Here, we report data from 4 experiments aimed at investigating the effects of anodal tDCS over the left ventrolateral prefrontal cortex (VLPFC) on verbal episodic memory. We evaluated tDCS-induced effects as a function of time of administration, nature of the memory encoding task, and age of the participants. A robust enhancement of memory performance was only found when anodal tDCS was delivered during intentional memorization. This enhancement was evident in young and older adults. tDCS applied during incidental memorization or during retrieval did not induce any modulation of memory performance, and memory was unaffected by offline administration before encoding or retrieval. These results show that the modulation of episodic memory functions by anodal tDCS over the left VLPFC is dependent upon the time of administration and the nature of the memory task. The findings may help profile the optimal stimulation protocols for neurorehabilitation interventions on individuals with memory decline.
在过去的十年中，已有多项研究调查了经颅直流电刺激（tDCS）对情景记忆能力的影响。然而，tDCS 影响记忆的具体条件在很大程度上仍不清楚。在这里，我们报告了 4 项实验的数据，旨在研究阳极 tDCS 对左腹外侧前额叶皮层（VLPFC）对言语情景记忆的影响。我们评估了 tDCS 诱导的影响，包括给药时间、记忆编码任务的性质和参与者的年龄。只有当阳极 tDCS 在有意记忆时给予时，才会发现记忆表现的明显增强。这种增强在年轻和老年成年人中都很明显。在偶然记忆或检索期间应用 tDCS 不会引起记忆表现的任何调节，并且离线给药在编码或检索之前不会影响记忆。这些结果表明，左 VLPFC 上的阳极 tDCS 对情景记忆功能的调节取决于给药时间和记忆任务的性质。这些发现可能有助于为记忆下降的个体的神经康复干预确定最佳刺激方案。
