The proposal responds to RFA-HD-14-012 by providing core services that advance the diagnosis, prevention, treatment, and amelioration of intellectual and developmental disabilities (IDD). The primary aim of the NEC is to leverage standard and cutting edge neurobehavioral and cognitive approaches to further our understanding of healthy and diseased brain anatomy, function, and pathophysiology. In order to realize this goal, measurement of neurobehavioral and cognitive outcomes is a crucial endpoint for studies of both atypical and typical development. The aims of the studies supported by the NEC, therefore, focus on developmental, cognitive, and behavioral outcomes in animal models of IDD and in children who have a variety of neurogenetic, neurodevelopmental, or acquired neurological disorders. Furthermore, advancement in the diagnosis, prevention, treatment, and amelioration of IDD is maximized through a multi-level, translational, approach that progresses from preclinical (animal) to human studies. Overall, the goal of the NEC is to guide investigators to use neurobehavioral/cognitive testing to assist in defining specific, yet complex, neurobehavioral and neuropsychological processes. Aims of the NEC are to: AIM 1: Provide services at a level appropriate to individual projects including maximizing test and technology development; AIM 2: Provide individual and group education and training to the DC-IDDRC community; and AIM 3: Promote and facilitate Core collaboration across projects. The importance of the NEC is to employ measures that link the underlying mechanisms of neurological disorders with behavioral and cognitive developmental outcomes. The NEC affords DC-IDDRC investigators access to a robust platform to improve access to state- of-the-art neurobehavioral and cognitive tools and to enhance the overall quality of preclinical and clinical neurobehavioral research being conducted throughout the DC-IDDRC. In addition, the Core improves efficiency by providing access to expert personnel and/or testing materials that maximize cost effectiveness.