Averaged weighted Spearman correlations between pretraining activity levels and neurofeedback learning success as measured by the difference between neurofeedback success in the last and the first neurofeedback run. Circle sizes represent the corresponding study's sample sizes. Further, the coloring scheme reflects the corresponding grouping of the subjects (healthy subjects/patients) and the studies (type of feedback, trained target region(s) and type of pretraining activity levels). Overall, no correspondence between pretraining activity levels and neurofeedback learning success was found, except for when only investigating pretraining activity levels during a functional localizer run. Abbreviations: amy, amygdala; DMN, default mode network; n.a., not applicable; no‐fb, no feedback; loc, localizer; ROI‐eng, ROI‐engaging