Apart from alcohol, few other pharmacological challenges have been used in the context of genetic research on the human EEG. Hynek et al. (1978) examined the effects of chlorpromazine (a dopamine antagonist) on the EEG in twins and found that drug-induced EEG changes, most notably, an increase in beta-band power, are influenced by genetic factors. Although drug challenge studies using the twin design are very scarce, they demonstrate that this approach can be used to determine whether and to what extent individual differences in response to psychoactive drugs are influenced by genetic factors.
