An important consideration is whether PLF adds sufficiently to the prediction of externalizing beyond EVK to justify increasing model complexity by adding another predictor. When frontal PLF and EVK were entered as dual predictors for externalizing diagnoses, QICu values for the dual predictor model were smaller than those for single predictor EVK models in most cases (see Table 2 for change in QICu values), despite many single predictor PLF models having no significant regression coefficients in Table 1. With one exception (predicting AAB using delta), the dual predictor model at the parietal site resulted in an improvement in fit over the EVK-only model. To summarize, 40 model fitting tests were carried out to see if a model that included both PLF and EVK predicted externalizing better than one using EVK alone, and in 85% (34/40) of the comparisons, the dual predictor model fit was better, pointing to the importance of PLF over and above EVK alone to the prediction of externalizing.
