Effects of motor practice on the temporal coordination of articulatory movements for non-native onset clusters: Kinematic and acoustic evidence using electromagnetic articulography

Abstract

Research on cross-language speech production has shown that part of the challenge of producing non-native clusters arises from difficulties with temporally coordinating the successive consonantal gestures within a cluster. However, it remains unclear whether the application of practice-based motor learning paradigms can improve or stabilize this aspect of non-native cluster production. This study uses electromagnetic articulography (EMA) to measure the effects of motor practice on the temporal coordination of articulatory movements for non-native onset clusters. Monolingual speakers of American English intensively practiced producing monosyllabic sequences containing non-native onset clusters (e.g., MGAT) over two consecutive days. EMA was used to capture lingual, labial, and jaw motion during successive repetitions. For properly-sequenced cluster repetitions, analysis of the EMA sensor trajectories showed that, over the course of practice, there was a general reduction in inter-gestural timing variability and increased overlap between adjacent consonantal gestures. Furthermore, some of these improvements were maintained to the second day, indicating that subjects started forming durable performance gains. Acoustic analyses also showed a reduction in the duration of epenthetic vowel errors (/mgæt/ → /məgæt/) produced throughout practice. Collectively, the findings suggest that motor practice can improve the temporal coordination of articulatory gestures affiliated with non-native clusters.