The goal of the present study is to assess behavioral (primary) effects of a multi-session cognitive training combined with transcranial direct current stimulation (tDCS). Many studies to date have found tDCS to be an efficient method to enhance various cognitive functions by modulating cortical excitability in young adults, but its behavioral impact and underlying mechanisms in pathological aging still need to be elucidated. Individuals with prodromal Alzheimer's disease, will participate in a three-week cognitive training with concurrent online tDCS application. Cognitive performance (primary) will be examined before, during and after the intervention, in order to draw conclusions about the effect of tDCS. In addition to cognitive training, a control group, receiving sham stimulation during training, will be assessed. Follow-up sessions to assess long-term effects are planned four weeks and seven months after the post assessment. Furthermore, to assess potential predictors of tDCS effects, functional and structural parameters will be measured with MRI. The results of the study will offer valuable insights into efficacy of combined tDCS and cognitive training, as compared to training alone, in individuals with prodromal stages of Alzheimer's disease. Moreover, improved understanding of tDCS effects on cognitive training performance and underlying neural correlates may help to develop novel approaches for modulating cognitive decline in healthy and pathological aging.