Assessment of developmental toxicity: neuropsychological batteries

Assessment of change in behavioral functioning in children as a function of neurotoxicity is not a trivial undertaking. Psychological tests, widely (though erroneously) considered to be the "gold standard" for measurement of behavior in humans, are not adequate for the task; they tap the structure of cognition, not the behavioral repertoire, and cannot (alone) address developmental change. Comprehensive neurobehavioral assessment must be undertaken within a multidisciplinary assessment strategy incorporating knowledge of brain and brain development, cognitive processes and their development, brain-behavior relationships, and detailed knowledge of neurotoxicants, their action and the exposure thereto. Initial assessment batteries must be adequately broad ranging and must incorporate strategies and data for evaluating the impact of predictable nonbrain variables; they must also be cost efficient to respond to the realities of funding and the exigencies of field testing. Measures of neuropsychological outcome are optimally characterized as they relate to behavioral domains specified in terms of the competencies of infants and children of different ages; relevant information is derived from demographic, socioeconomic, medical, developmental, and educational sources, as well as from detailed observational data and performance on psychological tests. Two levels of assessment are proposed.