Tracking developmental changes in articulatory strategy during childhood

Abstract

During development, children learn how to coordinate movements of the speech articulators in order to optimally achieve motor goals. It has been shown that variability in these coordinative patterns, or articulatory strategies, decreases over the course of childhood before ultimately stabilizing at adult-like levels. For example, the jaw becomes more tightly coordinated with the tongue and lips. Recent advances in real-time magnetic resonance imaging (rt-MRI) and analysis provide a means to characterize such articulatory strategies by quantifying how much the jaw, tongue, lips, velum, and pharynx contribute to constrictions of the vocal tract during speech. The articulators are segmented in reconstructed rt-MRI and constriction degrees are measured as the linear distance between opposing structures (e.g., tongue and palate). Change in constriction degree over time is decomposed into articulator contributions to characterize articulatory strategy. In this pilot study, we obtain quantitative biomarkers of articulatory strategies from a 10-year-old participant and compare them against those of 8 healthy adult participants. The study quantifies the difference between child and adult articulatory strategies in terms of how much each articulator contributes to constrictions of the vocal tract during speech and indicates how the articulator movements are coordinated with each other in time.