The willingness to apply cognitive effort plays a key role in disorders that affect decision making. For instance, overestimating the costs of cognitive effort relative to the benefits may impair planning and executive function in addiction and apathy and anhedonia in depression and Parkinson’s Disease. Functional neuroimaging studies implicate different prefrontal cortex (PFC) regions in these processes but lack the combined temporal and spatial resolution necessary to dissociate their roles and interactions. We are working on several related projects focused on mapping the components of cognitive effort regulation to distinct neural mechanisms in humans. We hope that discovering such mechanisms will enable novel biomarkers and brain stimulation targets for depression, Parkinson’s Disease and other disorders of decision-making.