AbstractSelection and integration of information based on current goals is a fundamental aspect of flexible goal-directed behavior. Reward motivation has been shown to improve behavioral performance across multiple cognitive tasks, yet the underlying neural mechanisms that link motivation and control processes, and in particular its effect on context-dependent information processing, remain unclear. Here, we used functional magnetic resonance imaging (fMRI) in 24 human volunteers to test whether reward motivation enhances the coding of behaviorally relevant category distinctions across the frontoparietal cortex, as would be predicted, based on previous experimental evidence and theoretical accounts. In a cued target detection categorization task, participants detected whether an object from a cued visual category was present in a subsequent display. The combination of the cue and the visual category of the object determined the behavioral status of the presented objects. To manipulate reward motivation, half of all trials offered the possibility of a substantial reward. We observed an increase with reward in overall activity across the frontoparietal control network when the cue was presented. Multivariate pattern analysis (MVPA) further showed that behavioral status information for the objects presented was conveyed across the network. However, in contrast to our prediction, reward did not increase the discrimination between behavioral status conditions in the stimulus epoch of a trial when object information was processed depending on a current context. In the high-level general object visual region, the lateral occipital complex, the representation of behavioral status was driven by visual differences and was not modulated by reward. Our study provides useful evidence for the limited effects of reward motivation on task-related neural representations.
Reward motivation enhances coding of task-set information in frontoparietal cortex
