The concept of plasticity describes the ability to respond to the negative health effects of ageing or illness with compensatory adaptation that enables continued health. In the cognitive domain, the term cognitive reserve is used for this. Cognitive reserve is built up over the course of a lifetime and thanks to various stimulating activities, and can have a positive influence on coping with illness. The aim of the project is therefore to assess cognitive reserve using a validated online questionnaire among participants at the Halle Study Centre and to analyse the influence of cognitive reserve on the development and management of disease.