In order to investigate the effects of age, gender and IQ on the correlation between NAcc connectivity and delay discounting, we repeated the correlation analysis adjusting for these variables. We first repeated the correlation analysis adjusting for age and sex. The new correlation maps (for lnk: Supplementary Figure S.3; for AUC: Figures S.5 and S.7) also show positive correlation between delay discounting and (or negative correlation between AUC and): (a) NAcc-vmPFC connectivity, (b) NAcc-left anterior PFC connectivity (pointed by the arrow) and (c) NAcc-right middle temporal gyrus connectivity, among other regions. We note that after adding the additional covariates the statistical significance of these findings decreased, and only the correlation with AUC remained after correcting for multiple comparisons (Supplementary Figure S.7); however, the general picture was unchanged suggesting that age and gender have minimal effects on the overall patterns observed.
