Genome-wide association tests with the frontal theta ERO phenotype to target stimuli were performed on 1560 samples from 117 of the 118 families genotyped; one of the 118 families was excluded because there were no theta ERO measurements available. Association testing was carried out assuming an additive model using the generalized disequilibrium test. Phenotype data was derived from multivariate linear regression models which were constructed from log-transformed theta power recorded at Fz, controlling for log-transformed age and stratified by gender and the residual values were fit to a standard normal distribution to create z-scores. Secondary analysis examined the topographic distribution of association signals in the KCNJ6 region using total theta power at Cz and Pz scalp locations.
