People do not always do what they believe is in their best interest. This is strikingly true of the addict, who characteristically goes through repeated cycles of resolution, transgression, and regret. But it is also evident in more commonplace phenomena like overeating, spending beyond one's means, over-indulgence in passive entertainment, and other bad habits too common to be considered pathological. At the same time, people are not powerless against this failing. In everyday life, people refer to their reliance on "self-control." Our lab is working towards a mechanistic understanding of self-control. In some of our work, we use functional Magnetic Resonance Imaging (fMRI). We are also interested in addiction, which brings the self-control struggle into the foreground.