Review Neural mechanisms for learned birdsong

Learning by imitation is essential for transmitting many aspects of human culture, including speech, language, art, and music. How the human brain enables imitation remains a mystery, but the underlying neural mechanisms must harness sensory feedback to adaptively modify performance in reference to the object of imitation. Although examples of imitative learning in nonhuman animals are relatively rare, juvenile songbirds learn to sing by copying the song of an adult tutor. The delineation of neural circuits for birdsong raises the promise that this complex form of vocal learning, which bears strong parallels to human speech learning, can be understood in terms of underlying neural mechanisms. This promise is now being more fully realized, with recent experimental advances leading to better understanding of the central motor codes for song and the central mechanisms by which auditory experience modifies song motor commands to enable vocal learning. Imitation is the foundation for transmitting much of human culture. Most importantly, the child’s ability to vocally mimic the speech of parents and peers forms the foundation for spoken language (Locke 1993). Despite the fundamental importance of speech learning to human societies, and the widespread use of vocal communication by other animals, vocal learning in non-human species is quite rare. Oscine songbirds (order: Passeriformes) produce learned courtship songs (Fig. 1) that are culturally trans-mitted from one generation to the next, affording an experimen-tally tractable system in which to study the neurobiological underpinnings of vocal imitation. Songbirds are a highly diverse group, comprising roughly 4000 species, and the song learning process has been studied in detail in only a small fraction (<10%) of these. Even this small sample reveals great diversity in the pace at which song is learned, the range of model songs juvenile birds will imitate, whether one or both sexes sing, and whether song serves primarily to attract mates or also is employed in territorial defense (for more detaile