Dr. Knudsen's current research focus is to study mechanisms of attention, learning, and strategies of information processing in the central auditory system of developing and adult barn owls, using neurophysiological, pharmacological, anatomical and behavioral techniques. Studies focus on the process of sound localization. Sound localization is shaped powerfully by an animal's auditory and visual experience. Experiments are being conducted to elucidate developmental influences, extent and time course of this learning process, and its dependence on visual feedback. The cellular mechanisms that underlie this example of learning are being studied to determine how experience adaptively alters the anatomical, pharmacological and functional properties of the brain in developing and adult animals. In addition, we study mechanisms of attention (gain control of sensory responses) and the rules by which auditory and visual information is combined into a single representation in the brain. Techniques offered in this laboratory include acoustic stimulation, extracellular recording, microstimulation, neuropharmacology, immunohistochemistry, anatomical pathway tracing, and behavioral analysis.