All statistical analyses were performed using SPSS (SPSS Inc., Chicago, USA). To investigate which of the measures (ERP amplitude measures, evoked ERO power measures or total ERO power measures) discriminated the two groups, MANOVAs were applied. The Pillai-Bartlet trace was used as the test statistic for the MANOVAs. Tests of multivariate normality were not carried out on the dependent variables, but the Kolmogorov-Smirnov test was performed on each dependent variable to check for univariate normality. Where dependent variables were not normally distributed, logarithmic transformation of the variables was applied.
