neither a main effect nor any interaction effect with any factors in the model. The RM-ANOVA results were extracted from the multivariate test statistics (http://www-01.ibm.com/support/knowledgecenter/SSLVMB_20.0.0/com.ibm.spss.statistics.help/alg_glmrm_within-subjects.htm) as the ERO data for the within-subjects factors did not adhere to sphericity assumptions (i.e., the equality of the variances of the differences between levels of the repeated measures factor such as region). In other words, an appropriate alternative for the sphericity assumption while analyzing the EEG data is to use multivariate tests on the within-subjects effects within the GLM repeated measures model [106–108], as used in the current study. Further, Bonferroni adjusted pairwise comparisons within each significant main and interaction effects were analyzed using estimated marginal means (EMM) and standard errors (SE). The BIS scores between LR and HR groups were analyzed using one-way ANOVA. Chi-square tests (Pearson χ2) were used to determine the significance levels for the prevalence rates of externalizing diagnoses between HR and LR groups. Likelihood ratio was used when any cell in the comparison had less than 5 observations. Pearson correlations were used to analyze the relationship between BIS scores and theta power.
