BEHAVIORAL MECHANISMS OF VOCAL IMITATION

City College Of New York, New York NY

Investigators

Linked publications & trials

Abstract

DESCRIPTION: Behavioral mechanisms of vocal imitation: Vocal imitation is an essential component of early language acquisition in human infants. It occurs intensively during infancy, but is much less efficient later in life, e.g., when acquiring a second language. A similar phenomenon occurs in songbirds: a zebra finch can accurately imitate a series of complex sounds during a sensitive period of its ontogeny, but as the bird grows up, it gradually loses the ability to imitate. It is not known how the bird alters sounds to achieve a specific imitation and we do not know how age may affect this process. This proposed research combines a novel experimental setup with powerful sound analysis techniques to induce song imitation in the zebra finch within a few days, tracking the dynamics of vocal imitation - as it occurs. Using those new tools, automated measurements of speed and accuracy of vocal imitation will be carried out under tight experimental control, in many animals simultaneously. The new technique makes it possible to examine how specific sounds are being transformed, gradually evolving to resemble the target sound model. Confining vocal imitation to a narrow time window will allow a systematic examination of the effect of age on vocal learning. Research will provide accurate, fully automated measurements of how fast imitation progresses, how many sounds are being copied simultaneously and how accurate the similarity to the song model is in birds of different age groups. Of particular interest are sound transformation skills that the bird gradually loses as it grows up. A parallel line of research will aim at factors that may predict the success of vocal imitation: measurements of weight gain, vocal repertoire prior to learning and hearing tests will be carried out to examine possible effects on the success of imitation. In addition, research will attempt to isolate inherited phenotypes of birds that differ inaccuracy or speed of imitation. Overall, this proposed research would examine, under controlled conditions, how vocal imitation emerges and what are the parameters that characterize vocal imitation in relation to age and inherited factors. It will provide the first comprehensive documentation of the vocal imitation process and will impose constraints on theories of early vocal learning. Accurate measurements of vocal imitation in real time, across age groups and across animals that differ in their imitation skills will provide neurobiologists with a new tool, allowing them to relate neuronal events to the specifics of vocal learning. The long-range goal is to broaden our understanding of factors that may govern vocal learning in human infants as well.