In the Netherlands Twin Register, we have estimated the heritability of a variety of EEG and ERP endophenotypes, and similar work has been undertaken by colleagues from twin registries around the world [30-43]; Table 1 illustrates the findings from these studies. A striking genetic contribution is found to almost all EEG and ERP traits. Resting EEG power is even among the most heritable traits in humans. This high heritability does not simply reflect 'trivial' heritable similarities in the composition of the skull or other tissue layers between electrode and brain. Almost identical heritability estimates are obtained when power is computed in signals from magnetoencephalography, which are almost undistorted by tissues covering the brain [44,45].
