Migraine patients show impaired cortical information processing between attacks with deficient habituation of pattern-reversal visual evoked potentials (VEP), and strong intensity dependence of auditory cortical evoked potentials (IDAP). This could be a genetic trait as certain genetic patterns are known for evoked potentials in healthy subjects. VEP-habituation and IDAP were studied in 40 migraine patients, i.e. pairs of 20 parents and their children. We developed a novel approach based on Monte Carlo statistics to selectively assess vertical familial influences. Both groups, parents and children, were characterized by abnormal VEP-habituation and IDAP. However, similarity between related pairs was far more pronounced than similarity between unrelated pairs. Assessed with a novel statistical approach, familial influences proved to be highly significant in determining cortical information processing in migraineurs, thus supporting the important role of genetic factors.