Birdsong: The Neurobiology of Avian Vocal Learning
Although many vertebrates literally sing out to communicate with other members of their species, the capacity for vocal learning is quite rare. Indeed, vocal learning has been convincingly demonstrated only for humans, songbirds, parrots, and certain species of hummingbirds, bats, and whales. Due to their behavioral diversity, esthetic qualities, and tractability as research subjects, oscine songbirds (Order: Passeriformes) have served as the focus of extensive investigations into the behavioral and neurophysiological mechanisms of vocal learning. Birdsong and human speech share numerous developmental features, including a dependence on auditory experience of an appropriate tutor, a reliance on auditory feedback to match one's own vocalizations to match the tutor model, and sensitive periods during which these auditory experiences influence vocal quality. The songbird brain contains a collection of interconnected brain nuclei, known as the song system, that are important to song learning, production, and perception. The amenability of the song system to detailed electrophysiological recordings makes the songbird's brain a rewarding place to search for the neural mechanisms that regulate sensitive periods for learning, facilitate prodigious feats of auditory memorization, and enable feedback-dependent vocal learning and maintenance. Today, we know much about song's function as a communication signal, the process by which young birds learn to sing, and the neural substrate for singing and song learning. © 2009 Elsevier Ltd All rights reserved.
