The investigator will perform a complex cognitive training program. Forty patients with aMCI (20 with high cognitive reserve, 20 with low cognitive reserve) will be recruited in this study. Since the patients are recruited consecutively, an estimated overall number of 80 will be included and receive the training of whom about 40 will meet the inclusion criteria for our cognitive-reserve-study (high or low cognitive reserve). Data of the whole group will be used to analyze the potential impact of white matter lesions on response to the intervention. Cognitive effects of the intervention will be evaluated by neuropsychological testing. Neurofunctional and neurostructural changes depending on cognitive reserve will be measured using resting state fMRI and diffusion tensor imaging (DTI).