| dc.description.abstract | Song learning in oscine birds shares many similarities with vocal imitation underlying the development of human speech and language. The Bengalese finch (Lonchura striata domestica) is one of few species with left hemispheric dominance over song production and discrimination. This parallels the left hemispheric dominance seen with human speech production and perception. It has been argued that lateralized neural control facilitates the vocal learning that underlies human speech. Given the lateralized control of song production, the Bengalese finch is a useful model for exploring avian parallels with human vocal learning. We sought to determine whether unilateral brain lesions would differentially contribute to the degree of song degradation and re-acquisition. The HVC is a premotor nucleus that is critical for control of timing and sequencing of syllables, similar to premotor cortical contributions to speech production in humans. We explored lesions to the left or right HVC of two different sizes: microlesions and full lesions. Microlesions were performed to transiently disrupt song production and enable quantification of song recovery whereas full lesions would induce more long term damage and to determine whether the side of the lesion will affect the rate of song recovery. Damage to the left or right HVC resulted in equivalent changes in song structure for all measured spectral and temporal parameters regardless of lesion size. Furthermore, the side of the microlesion did not affect rate of recovery of song production. Although the final motor commands to the syrinx are highly lateralized to control particular frequency ranges of song syllables, the premotor control of song production is not lateralized. These data illustrate the importance of bilateral, synchronized neural control underlying song production. | |
