CAPS Lab Director, Dr. Masapollo, was recently awarded Research Opportunity Seed Funds (ROSF) from UF Research. The planned experiments, in collaboration with Drs. Susan Nittrouer (PHHP, SLHS) and Joseph Antonelli (LAS, Statistics), will examine the complex interplay between the development of speech motor control, speech perception, and phonological representations in 4- to 6-years-olds. The project abstract is given below.
Elucidating the mechanisms that underlie the production and perception of speech is critical both to our basic understanding of human language processing and to the effective design of rehabilitation protocols for communication disorders. Speakers must rapidly coordinate the actions of multiple articulators (such as the lips, tongue, and jaw) to produce the overlapping vocal tract movements necessary for fluent, natural-sounding speech. In decoding the resulting acoustic signal, listeners must recognize detailed phonological structure (such as the successive consonants and vowels) in the speech stream (i.e., phonological sensitivity). Yet the motor, perceptual, and linguistic computations required are highly complex, as anyone attempting to produce and listen to speech in a foreign language can readily attest. Nevertheless, in the first five years of life, normally developing children make remarkable progress in acquiring these skills. Research proposed in this application focuses on explicating the precise nature and development of the relation between speech motor control and phonological sensitivity in early childhood. This project seeks to test the novel hypothesis that speech motor control and phonological sensitivity emerge in a scaffolded manner, meaning that as one improves it supports further development of the other. This hypothesis will be tested using a highly integrated combination of kinematic, acoustic, and modeling studies organized around the MIPA model of phonological acquisition, which proposes that the development of speech motor control contributes significantly to phonological sensitivity. A longitudinal study will experimentally assess children from 4- to 6-years of age (at 6-month intervals) on their ability to coordinate lip, tongue, and jaw motion during speaking tasks, using electromagnetic articulography. A further battery of tests at the same ages will assess cognitive and linguistic development. Specific questions to be addressed include: How and when do children learn to coordinate among muscles and articulators to produce speech? How does inter-articulator speech production measured at specific ages in childhood compare to changes in such performance across ages (growth curves) with regard to predicting concurrent and future phonological awareness skills (cross-lagged models)? The resulting models will constitute a significant milestone in the decades-old effort to understand the development of perception-action linkages for speech and will pave the way for designing and testing targeted interventions for children with developmental disabilities that affect speech production, such as stuttering, as well as language-related disorders arising from poor sensitivity to phonological structure, such as dyslexia.