Grant: Discovery Grants Program - Individual

Speech production is a complex skill that is acquired rapidly during early childhood development. Notably, there are dramatic growth-related changes that occur during development as speech is learned, including physical (e.g., muscle strengthening and teething) and cognitive development. Further, as humans age, they experience many age-related changes that impact speech, both physical (e.g., muscle weakness, the potential loss of teeth, and changes in hearing thresholds) and cognitive (e.g., impaired attention and memory). Auditory feedback (AF), or the sound of one's voice, has been shown to play a key role in the development and maintenance of fluent speech production. However, the way the brain processes information from the auditory signal during the acquisition and maintenance of fluent speech is unclear. Further, changes in `AF control of speech' across the lifespan remain unclear. My lab utilizes frequency-altered auditory feedback (FAF) in real-time to examine how changes to AF during vocalization influence vocal productions. By pairing this FAF technique with electroencephalography (EEG) we can explore the neural correlates of AF control of speech production. The long-term objective of my research program is to further our understanding of AF control of speech. To this end, my research will explore how the brain processes information from the auditory signal while controlling the motor movements required for fluent speech production. By examining event-related potential (ERP) responses and the power and phase coherence of neural oscillations recorded using EEG, my research will advance our understanding of how auditory-motor interactions are represented in the brain. Further, by comparing and contrasting ERP and neural oscillatory data analysis techniques, this research will determine the relative efficacy of these techniques for understanding auditory-motor interactions in the brain. By exploring vocal and EEG responses across a large age range (2-89 years) using manipulations of both fundamental frequency (vocal pitch) and formant frequencies (vowel sounds), this research will establish important benchmarks that will aid in our understanding of auditory processing, speech development, and speech perception and production. Further, modelling these responses across the lifespan (ages 2-89 years) will help facilitate the early detection of speech and communication disorders. This work will provide the foundation to examine how irregular speech may manifest in populations exhibiting atypical neural mechanisms supporting speech production. Thus, this research will inform theoretical, methodological, and applied knowledge that will ultimately support the maintenance of optimal brain functioning across the lifespan.