Functional integration processes underlying the instruction-based learning of novel goal-directed behaviors.

摘要

How does the human brain translate symbolic instructions into overt behavior? Previous studies suggested that this process relies on a rapid control transition from the lateral prefrontal cortex (LPFC) to the anterior striatum (aSTR) and premotor cortex (PMC). The present fMRI study investigated whether the transfer from symbolic to pragmatic stimulus-response (S-R) rules relies on changes in the functional coupling among these and other areas and to which extent action goal representations might get integrated within this symbolic-pragmatic transfer. Goal integration processes were examined by manipulating the contingency between actions and differential outcomes (i.e. action goals). We observed a rapid strengthening of the functional coupling between the LPFC and the basal ganglia (aSTR and putamen) and orbitofrontal cortex (OFC) as well as between the LPFC and the anterior dorsal PMC (pre-PMd), the anterior inferior parietal lobule (aIPL), and the posterior superior parietal lobule (pSPL). Importantly, only some of these functional integration processes were sensitive to the outcome contingency manipulation, including LPFC couplings with aSTR, OFC, aIPL, and pre-PMd. This suggests that the symbolic-pragmatic rule transfer is governed by principles of both, instrumental learning (increasingly tighter coupling between LPFC and aSTR/OFC) and ideomotor learning (increasingly tighter coupling between LPFC and aIPL/pre-PMd). By contrast, increased functional coupling between LPFC and putamen was insensitive to outcome contingency possibly indicating an early stage of habit formation under instructed learning conditions.