| Abstract | Human language is an action wherein one plans for, produces, and terminates sound production. Errors in motor planning for initiation and cessation of speech lead to vocal dysfluency. Motor control of respiration is critical for the myoelastic aerodynamic mechanism of sound generation that is used by humans and many other vocalizing animals. Developing our understanding of how the forebrain directly modulates brainstem respiratory circuitry to produce sound is essential for understanding language initiation. Songbirds are an animal model for speech production in humans because of the similarities between song learning and production and language acquisition and speech production. Zebra finches (Taeniopygia guttata) sing a learned song that is composed of a stereotyped sequence of song syllable (motif), which is preceded by a variable number of introductory notes (1-7 notes). Here we explore whether the respiratory patterns producing introductory notes are a form of song motor preparation by comparing similarity in respiratory patterns during the introductory note sequence compared to the first song syllable. The results indicate that introductory notes are not preparatory for song, but rather serve as a form of motor practice to refine their production. As the sequence progresses, there is a pattern of decreasing duration of introductory notes as they approach song, particularly during the expiratory pulses of the sequence, which supports the notion that introductory notes are used by birds to modulate their respiratory rate during quiet breathing to generate the faster respiratory tempo needed during song production. Overall, the study sheds light on the role of introductory notes in zebra finch song production and provides a foundation for future studies aimed at exploring the neural circuits necessary for preparing to sing. |
