Enhancing value-based learning by focalized tDCS (transcranial direct current stimulation)

适应性行为要求个人学习并表示他们的选择和决定结果之间的偶然性，以根据情景需求调整行为。这种基于价值的学习也是顺序决策的基础，在顺序决策中，当前选择的结果只有在几个决策阶段后才会变得明显。基于价值的学习对于适应一生不断变化的环境至关重要，众所周知，在衰老和与衰老相关的疾病中，这种学习会减少。鉴于基于价值的顺序决策对于不同年龄段的人来说是一项与生态相关的日常生活任务，本项目将专门研究个性化的经颅直流电刺激(TDC)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(例如痴呆症及其前驱疾病)患者的治疗，这些患者的基于价值的学习和决策能力也受到损害。在更广泛的研究单位的背景下，本研究是调查tdcs对跨功能领域的学习和记忆形成的影响以及健康人类寿命的八个实证项目之一。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第一次分析潜在的神经机制和行为刺激反应的预测因素，不仅在每个项目中，而且还与研究单位的方法导向项目协调，以研究不同任务和功能领域之间的关系。该项目将就tdcs如何调节基于价值的顺序决策提供独特的信息，从而补充项目7中tdcs诱导的基于学习的自适应控制的增强的研究(Pi Fischer)。总而言之，研究组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变化的潜在变化的理解。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和P10中)，从而推动未来tdcs在健康和疾病中的实验和翻译应用。

Adaptive behaviour requires individuals to learn and represent contingencies between their choices and the outcomes of their decisions to adjust behaviour according to situational demands. Such value-based learning also underlies sequential decision making, in which the outcome of a current choice only becomes apparent after a few decision stages. Value-based learning is crucial for adapting to changing environments throughout life and is known to decline in aging and aging-associated diseases. Given that value-based sequential decision is an ecologically relevant task in everyday life for people of different ages, 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) for whom the abilities of value-based learning and decision making are also impaired. Within the broader context of the Research Unit, the present study is one of eight empirical projects investigating tDCS effects on learning and memory formation across functional domains and the healthy human lifespan. The highly systematic and coordinated approach pursued by these empirical projects will allow us, for the first time, to analyse the underlying neural mechanisms and predictors of behavioural stimulation response not only within each project, but also coordinate with method-oriented projects in the research unit to study relations between different tasks and functional domains.This project will contribute unique information on how tDCS modulates value-based sequential decision making, thereby complementing the investigation of tDCS-induced enhancement of learning-based adaptive control in Project 7 (PI Fischer). Collectively, the results of the empirical projects of the Research Unit 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 and P10), thereby advancing future experimental and translational applications of tDCS in health and disease.