Over the last 50 years, studies on brain-injured adults have demonstrated that the right hemisphere has a selective ability to process emotional information. Clinical observations of children with lateralized brain injury suggest that right hemisphere damage (RHD) may produce chronic impairment of social and emotional behaviors. The purpose of this proposal is to test the hypothesis that, in children, as in adults, there is a similar specialization of the right hemisphere for processing emotional information. Specifically, the following questions are addressed: (1) do children with RHD demonstrate deficits in the comprehension of the affective expressions of others? and (2) in the ability to produce affective displays through facial and vocal channels? (3) are these deficits reflected by significant differences in the ratings of parents, teachers and the children themselves on standardized questionnaires dealing with social behaviors an social adaptation? (4) is it possible to identify these deficits within a naturalistic observational setting? (5) are there age-related differences in the manifestations of RHD? (5) can modularity be demonstrated to exist in children as it does in brain-damaged adults? (i.e., dissociation of the production of affect from its comprehension, and of facial from vocal processing). The experiments are designed so that alternative hypotheses regarding hemispheric specialization for emotion can also be tested. Three groups: RH damaged (RHD), LH damaged (LHD) and normal controls (NHD), over three age groups: (5-6 years; 8-9 years; and 14-15 years) will be studied. Groups will be matched for I.Q., sex and size and location of lesion. Performance on neuropsychological tasks which deal with the comprehension and production of facial and vocal affective displays, ratings on questionnaires dealing with social behaviors, and the child's behaviors in the laboratory situation will be studied. These studies are being conducted in order to explore the acquisition of social/emotional behaviors in brain-injured children, and may shed light on important aspects of brain development and function.