Reward Enhances Connectivity between the Ventral Striatum and the Default Mode Network

The default mode network (DMN) is involved in social, cognitive, and affective functions, but its role in coordinating with other brain regions depending on context was unclear. Using a novel network-based psychophysiological interaction analysis on reward task data from the Human Connectome Project, the DMN showed decreased activation during the task, while other networks (executive control, frontoparietal) increased activation. Reward experience enhanced task-dependent connectivity between the DMN and the ventral striatum, an effect specific to the DMN. The strength of this connectivity correlated with personality traits related to openness, advancing understanding of how the DMN contributes to brain systems during tasks and relates to individual differences.

Study at a glance

Abstract

Abstract The default mode network (DMN) has been theorized to participate in a range of social, cognitive, and affective functions. Yet, previous accounts do not consider how the DMN contributes to other brain regions depending on psychological context, thus rendering our understanding of DMN function incomplete. We addressed this gap by applying a novel network-based psychophysiological interaction (nPPI) analysis to the reward task within the Human Connectome Project. We first focused on the task-evoked responses of the DMN and other networks involving the prefrontal cortex, including the executive control network (salience network) and the left and right frontoparietal networks. Consistent with a host of prior studies, the DMN exhibited a relative decrease in activation during the task, while the other networks exhibited a relative increase during the task. Next, we used nPPI analyses to assess whether these networks exhibit task-dependent changes in connectivity with other brain regions. Strikingly, we found that the experience of reward enhances task-dependent connectivity between the DMN and the ventral striatum, an effect that was specific to the DMN. Surprisingly, the strength of DMN-VS connectivity was correlated with personality characteristics relating to openness. Taken together, these results advance models of DMN by demonstrating how it contributes to other brain systems during task performance and how those contributions relate to individual differences.