Enhancing novel word learning by focalized transcranial direct current stimulation

学习新单词的能力是发育中的和成人大脑中语言习得的关键方面，众所周知，在正常衰老和与年龄相关的疾病中，这种能力会下降。由于新词学习在工作和休闲环境中对日常生活具有很高的生态有效性和相关性，本项目将专门研究个性化的经颅直流电刺激(Tdcs)增强这一过程的神经机制和预测因素。从长远来看，该项目的成果将有助于改善神经退行性疾病(如痴呆症及其前驱疾病)或神经损伤(中风后失语症)影响语言(再)学习的患者的治疗。在更广泛的研究单位(RU)的背景下，本研究是调查tDCs对跨功能领域的学习和记忆形成的影响的八个项目之一(项目1-8)和健康的人类寿命。这些经验项目所追求的高度系统和协调的方法将使我们能够首次分析潜在的神经机制和行为刺激反应的预测因素，不仅在每个项目内，而且在不同的任务和功能领域(项目9)。本项目将提供关于tDCs如何调节言语情景记忆形成的独特信息，从而补充项目4(Pi Hartwigsen)关于tDCs诱导的言语工作记忆增强的研究(Pi Hartwigsen)。与使用类似学习范式研究视觉-空间情节记忆形成(Pi Flöel)的项目1的结果相比较，将允许调查各自结果的领域特异性。总而言之，RU的经验项目的结果将增加我们目前对tdcs诱导的神经网络效应、其区域特异性、刺激效应个体间差异的潜在机制以及由于年龄段的潜在变化的理解。从方法学的角度来看，在这些项目中获得的数据将有助于优化和验证当前流动的生物物理模型(在P9+10)，从而推动未来tdcs在健康和疾病中的实验和翻译应用。

The ability to learn new words is a crucial aspect of language acquisition in the developing and adult brain and known to decline in normal aging and age-associated disease. Because of the high ecological validity and relevance of novel word learning for everyday life in work and leisure contexts, this project will specifically investigate the neural mechanisms and predictors underlying enhancement of this process by individualized, focal transcranial direct current stimulation (tDCS). In the long-run, outcomes of this project will contribute to improving treatment of patients with neurodegenerative diseases (e.g., dementia and its precursors) or neurological injury (post-stroke aphasia) affecting language (re-)learning. Within the broader context of the Research Unit (RU), the present study is one of eight projects investigating tDCS effects on learning and memory formation across functional domains (Projects 1-8) and the healthy human lifespan. The highly systematic and coordinated approach pursued by these empirical projects will allow for the first time analyzing the underlying neural mechanisms and predictors of behavioural stimulation response not only within each project, but also across the different tasks and functional domains (Project 9).The current project will contribute unique information on how tDCS modulates verbal episodic memory formation, thereby complementing the investigation of tDCS-induced enhancement of verbal working memory in Project 4 (PI Hartwigsen). Comparison with results obtained from Project 1, that uses a similar learning paradigm to investigate visuo-spatial episodic memory formation (PI Flöel), will allow to investigate domain specificity of the respective outcomes. Collectively, the results of the empirical projects of the RU will increase our current understanding of tDCS-induced neural network effects, their regional specificity, the mechanisms underlying inter-individual variability of stimulation effects, and potential changes due to chronological age. From a methodological point of view, data acquired in these projects will contribute to optimizing and validating biophysical models of current flow (in P9+10), thereby advancing future experimental and translational applications of tDCS in health and disease.