Fiori Valentina, Nitsche Michael, Iasevoli Luigi, Cucuzza Gabriella, Caltagirone Carlo, Marangolo Paola
IRCCS Fondazione Santa Lucia, Roma, Italy; Università degli Studi di Roma Tor Vergata, Roma, Italy.
Department Psychology and Neurosciences, Leibniz Research Center for Working Environment and Human Factors, Dortmund, Germany.
Behav Brain Res. 2017 Mar 15;321:170-175. doi: 10.1016/j.bbr.2016.12.044. Epub 2017 Jan 3.
For the past few years, the potential of transcranial direct current stimulation (tDCS) for the treatment of several pathologies has been investigated. In the language domain, several studies, in healthy and brain-damaged populations, have already shown that tDCS is effective in enhancing naming, repetition and semantic word generation. In those studies, different tDCS electrode configurations have been tested, however, a direct comparison between different montages in verbal learning has never been conducted. In this study, we aimed to explore the impact of bihemispheric and unihemispheric tDCS on verbal learning task performance in two groups (young vs. elderly). Fifteen healthy volunteers participated per group. Each participant received three stimulation conditions: unihemispheric anodal tDCS over the left temporal area, bihemispheric tDCS over the left (anodal) and right (cathodal) temporal areas and a sham condition. During active stimulation, tDCS (20min, 2mA) was applied while each participant learned twenty pseudowords (arbitrarily assigned to corresponding pictures). No significant differences were found between the three conditions for the young group with regard to accuracy and vocal reaction times. In contrast, in the elderly group, real stimulation improved performance compared to sham but bihemispheric tDCS was more efficient than unilateral stimulation. These results suggest that bihemispheric stimulation is more effective in improving language learning but this effect is age-dependent. The hypothesis is advanced that cortical changes in the course of aging might differentially impact on tDCS efficacy on behavioral performance. These data may also have implications for treatment of stroke patients with language impairment.
在过去几年中，人们对经颅直流电刺激（tDCS）治疗多种疾病的潜力进行了研究。在语言领域，一些针对健康人群和脑损伤人群的研究已经表明，tDCS在增强命名、复述和语义词语生成方面是有效的。在这些研究中，已经测试了不同的tDCS电极配置，然而，从未对言语学习中不同电极组合进行过直接比较。在本研究中，我们旨在探讨双侧和单侧tDCS对两组（年轻人与老年人）言语学习任务表现的影响。每组有15名健康志愿者参与。每位参与者接受三种刺激条件：左侧颞区的单侧阳极tDCS、左侧（阳极）和右侧（阴极）颞区的双侧tDCS以及假刺激条件。在主动刺激期间，当每位参与者学习20个伪词（随机分配给相应图片）时施加tDCS（20分钟，2毫安）。在准确性和语音反应时间方面，年轻组的三种条件之间未发现显著差异。相比之下，在老年组中，与假刺激相比，真正的刺激提高了表现，但双侧tDCS比单侧刺激更有效。这些结果表明，双侧刺激在改善语言学习方面更有效，但这种效果取决于年龄。有人提出假说，衰老过程中的皮质变化可能对tDCS对行为表现的疗效产生不同影响。这些数据也可能对语言障碍中风患者的治疗有启示。
