longer—in other words, giving us a longer-lasting "chocolate high." So while chocolate does not contain the same active chemicals as marijuana, there is some similarity in the effect that both substances have on our brains.
Other scientists have used brain scanners to study how brain activity changes when we eat chocolate. Scanners like this are based on the neurospsychological idea that different parts of our brains have sometimes quite specialized functions—even to the extent that some bits work almost like discrete modules. In 2001, as part of their research into eating disorders, Dana Small and her colleagues asked their experimental subjects to eat chocolate until well beyond the feeling of satisfaction. They noted one set of brain structures were active when people were still finding the chocolate pleasant (specifically, the subcallosal region, caudomedial orbitofrontal cortex (OFC), insula/operculum, striatum and midbrain), while an entirely different set became active (parahippocampal gyrus, caudolateral OFC and prefrontal regions) once people had eaten too much. Too much chocolate is not necessarily bad for you, but your brain certainly might see it that way.