the amygdala, which orchestrates emotion. the try yay tum that gets recrueted for habit and also drug addiction. striatum. there is cognitive control of emotion, whether it's appropriate to particular a particular emotional response in this context versus another that is mediated by a high level structure called the pre-frontal cortex and controls these two other structures, the amygdala and striatum. all of them are influenced by a pleasure system in the brain. now one of the striking things about this circuit for emotion and particularly the dopamine pathway is it is involved in a number of diseases states. so it's disturbed in schizophrenia, in parkinson's disease, and it also cooperative in addictive disorders. so drug use such as cocaine and heroine hijack the system. and one of the great insights that you'll hear is exactly how this occurs. these drugs simulate the activation of this system. they take it over. >> are there stages of addiction? >> there are several well-defined stages of addiction too begin with, there's