Recent advances in behavioral and cognitive neuroscience have helped dissociate the functional role of fronto-striatal circuits in learning and decision making from that of the medial temporal lobes – specifically the hippocampus. Integrating computational modeling, patient studies, functional brain imaging, behavioral genetics, and comparative studies in rodent models, we argue that error-correction learning is a building block for a wide range of cognitive functions that depend on fronto-striatal circuits and their dopaminergic afferents. In contrast, the ability to generalize appropriately from newly learned associations to novel contexts and task demands depends critically on the formation of appropriate representations for new experiences, a process that relies on the hippocampus and other structures in the medial temporal lobes. These findings have lead to the development of the Rutgers Cognitive Assessment Battery, which we have used to further understanding, assessment, and prediction of cognitive deficits and their progression in several disorders that involve these brain systems: Parkinson's disease, Alzheimer's disease, and schizophrenia. In more recent studies, we have begun evaluating their relevance to other disorders such as dystonia, cocaine addiction, and frontotemporal dementia.
