"The images show the anterior cingulate cortex (ACC) -- the part of the brain that recognizes a situation in which self-control is needed and says, "Heads up, there are multiple responses to this situation and some might not be good" -- fires with equal intensity throughout the task. However, the dorsolateral prefrontal cortex (DLPFC) -- the part of the brain that manages self-control and says, "I really want to do the dumb thing, but I should overcome that impulse and do the smart thing" -- fires with less intensity after prior exertion of self-control. Loss of activity in the DLPFC might be the person's self-control draining away. The stable activity in the ACC suggests people have no problem recognizing a temptation. Although they keep fighting, they have a harder and harder time not giving in." - Adriano from Bookmarklet