“…This ability appears to be meditated, at least in part, by the hierarchical organization of prefrontal cortico-basal ganglia-thalamic networks [15,16,17] that are organized in such a way that anterior regions, reflecting more abstract task representations, have a stronger influence on more posterior regions, reflecting more concrete task goals, than vice versa [18]. The prefrontal networks are also thought to have hierarchically organized error signals that facilitate learning complex and conditional rules [19,20], and more rostral areas (higher in the hierarchy) appear to be engaged during both rumination [21,22] and imaginative play [23,24,25], suggesting a common underlying computation [26]. Thanks to the phasic dopaminergic signals from midbrain regions [27,28,29] these pathways are also capable of learning action values, where rewarded (or punished) actions become more (or less) likely to be executed in the future.…”