Jerffrey Johnson's lab is involved in computational neuroscience. Our specific interest is the role of nigrastriatal dopamine (via D1 and D2 receptor subtypes) on corticostriatal pathways during the acquisition of a learned behavior. However, the technology by which we implement the model allows us to collaborate with neuroscientists investigating many other aspects of basal ganglia function, including motivation, cocaine addiction, and Parkinson’s disease. We have a recursive, top-down modeling approach. We create virtual instances of classic behavioral experiments, such as multiple T-mazes and shuttle-boxes. We then develop biologically-plausible neural network (mathematical) models that are capable of replicating the whole-animal behavioral characteristics of rats that are trained in these experiments. Finally, we map the individual terms of the model to components and pathways within the basal ganglia. The mappings form a set of experimentally testable hypotheses as to their information processing functions of the basal ganglia components. Finally, each term is itself a model and can be further expanded using our object-oriented programming technology.