We plan to study auditory evoked potentials (AEPs) in both clinical neurological disorders and animal experiments to define neural mechanisms of the generation of these potentials and their application to disordered brain function. In particular, we will study in experimental animals the role of cells and nerve fibers in generating far-field auditory brainstem components using specific lesion methods and in an in-vitro model system using nerve fibers passing between fluid compartments of different volumes and impedances. Long-latency AEPs related to the encoding of words and tones and their subsequent memorization will be studied in normal subjects and patients with focal hemispheric lesions to define neural correlates of language processing and auditory memory. The definition of binaural processes relevant for sound localization will be defined in middle and long-latency AEPs by the occurence of binaural interaction components and related to several psychoacoustic measures in normal subjects, patients with neurological lesions, and in children during maturation.