 When an action is followed by an increase in dopamine activity, the basal ganglia circuit is altered in a way that makes the same response easier to evoke when similar situations arise in the future.This is a form of operant conditioning, in which dopamine plays the role of a reward signal.In the language used to discuss the reward system, "reward" is the attractive and motivational property of a stimulus that induces appetitive behavior (also known as approach behavior) and consummatory behavior.