A major common concern in ageing is the decrease of mental abilities and thus the loss of autonomy. The incidence of dementia exponentially increases in age, but also healthy aged individuals typically exhibit deficits in cognitive functions. However, the onset and progression of such age-related changes shows a high individual variability. Thus, many senior citizens still enjoy their cognitive abilities, whereas others may show signs of cognitive impairments already early in their life. The biological basis of this variation is not fully understood, but besides the environment also the genetic factors have a strong impact, because the heritability of cognitive abilities is above 50 % in middle and old aged individuals. Understanding the progress of age-related changes in brain functioning is a key step for a treatment aimed to limit the age-related cognitive decline.