The basal ganglia contain 'go' and 'no-go' circuits that regulate action initiation and prevention.

“The ventral striatum is part of this thing called, the basal ganglia. The basal ganglia has sort of two circuits within it. One circuit is involved in getting us to do things, like I'm going to get up tomorrow and I'm going to run five miles first thing in the morning. I don't know if I'm actually going to do that, but I'm just using that as an example. Another circuit within the basal ganglia, is a no-go circuit, it's the one that says, no, I'm not going to go for the second cookie or the third cookie. I'm not going to eat that. And then the go circuit would be the one that's responsible for instead eating something else.”