Brain Stimulation Over the Frontopolar Cortex Enhances Motivation to Exert Effort for Reward

Loss of motivation is a characteristic feature of several psychiatric and neurological disorders. However, the neural mechanisms underlying human motivation are far from being understood. Here, we investigate the role that the frontopolar cortex (FPC) plays in motivating cognitive and physical effort exertion by computing subjective effort equivalents. We manipulated neural processing with transcranial direct current stimulation targeting the FPC while 141 healthy participants decided whether or not to engage in cognitive or physical effort to obtain rewards. We found that brain stimulation targeting the FPC increased the amount of both types of effort participants were willing to exert for rewards. Our findings provide important insights into the neural mechanisms involved in motivating effortful behavior. Moreover, they suggest that considering the motivation-related activity of the FPC could facilitate the development of treatments for the loss of motivation commonly seen in psychiatric and other neurological disorders.