Frontomedian activation depends on both feedback validity and valence: fMRI evidence for contextual feedback evaluation

Activation within the posterior frontomedian cortex (pFMC) is suggested to be involved in decision conflict, which typically emerges whenever one does not know which action to choose in order to receive a positive outcome. Decision conflict attenuates due to learning which is often indicated by and therefore confounded with the receipt of increasingly frequent positive and decreasingly frequent negative feedback. The present functional Magnetic Resonance study aimed to disentangle the influence of the factors processing of negative feedback and contextual feedback evaluation on pFMC activation. Participants performed a forced choice paradigm in which they had to decide which one out of two competing stimuli would win in a virtual competition game. In one condition (rule learning, RL), participants were provided with valid feedback so that contextual feedback evaluation had a guiding function for action and thus enabled learning. In contrast, participants received no valid information from feedback in another condition (putative learning, PL) and hence could not learn on the basis of contextual feedback evaluation. However, a learning effect in the latter condition was simulated by gradually increasing the frequency of positive feedback and decreasing the frequency of negative feedback according to a learning model which was derived from pilot data. Importantly, participants were naive with respect to feedback manipulations. Beyond confirming pFMC activation for decision conflicts, a significant interaction between validity and valence of feedback in pFMC revealed the specific contribution of contextual feedback evaluation processes on activation of this area. Not the processing of negative feedback per se, which was found to elicit activation within anterior cingulate cortex, but the evaluation of feedback against the background of the current mental model is suggested to be reflected by pFMC activation.