We chose to parse our sample into three groups based on chronological age for several reasons. First, our previous paper with a subset of this sample (Crowley et al., in press) suggested this was a viable way to characterize age trends. Second, recent adolescent reward processing work suggests that some age related changes could be non-linear and a group based approach we felt was better for exploring this possibility. Third, the frequency by time array resulting from an ERSP or ITC analysis was better suited to group based comparisons for our implementation of FDR. We might have considered pubertal development as another option, or one to be considered in conjunction with chronological age. Despite this, we did identify age related changes in feedback processing, even among our 13-14 and 15-17-year-old groups, across both ERSP and ITC, with ITC effects surviving a more robust FDR statistical threshold. Recent adolescent neuroimaging studies reward processing and feedback learning have collapsed across these age ranges (Cohen et al., 2010; Galvan et al., 2006; van de Vijver et al., 2011), but our data suggest there
