Abstract: Method for checking the validity of reactions of test subjects, wherein a stimulus is demonstrated to the test subject, wherein evoked potentials are derived from the brain wave curves or the brain areas are depicted by functional imaging methods, and a reaction time task is assigned to the test subject and the reaction is measured, wherein the readiness potentials and/or the event-related potentials (ERPs) and/or the components of the ERPs and/or the event-related desynchronization (ERD) of the brain wave curve is derived and/or the brain areas are depicted by functional imaging methods.