The work proposed will increase our understanding of brain pathways used for the acquisition of a complex skill and the way they are connected and altered by experience. The subjects to be used are two species of songbird, the canary and zebra finch, that learn their song by imitating sounds they hear. Anterograde and retrograde tracers will be used to study the connectivity -- inputs and outputs -- of parts of the brain involved in the control of this learned behavior. Extracellular and intracellular electrodes will be used to characterize the electrical activity of neurons during song production and at the time the animal is presented with various sounds. Among the questions asked are, what is the relation between sound input and vocal output?, and how are pathways that mediate this relation affected by experience, sex, season and hormonal variables? Another question asked is how do anatomically symmetrical pathways for singing function so as to generate an asymmetry in manifest control? The health relatedness of this work comes by way of the information it might contribute towards an understanding of the mechanisms that determine the "when", "what", "how much" and "how" of learning, so that malfunction of these higher functions of the vertebrate brain can be approached in a more scientific manner than at present. An added expectation, based on preliminary observations, is that an understanding of the kinds of brain plasticity used in learning in adulthood may tell us about the brain's potential for self-repair and the factors that control it.