Developmental interactions between phonology and the lexicon in English-speaking toddlers

Abstract

This study examined the relationship between phonological development and development of the receptive and expressive lexicons across a ten-week period. Also, it investigated whether phonological accuracy during picture naming or real-word repetition at the initial assessment was a better predictor of vocabulary ability at follow-up. In initial (Time 1) and follow-up (Time 2) assessments across ten weeks, 44 English-speaking children (19-31 months) participated in two speech production assessments (picture naming and real-word repetition) and parents completed the MacArthur-Bates Communicative Development Inventory (MBCDI; Reese & Read, 2000). The present findings confirm that speech accuracy is a predictor of receptive and expressive vocabulary. Phonological development at Time 1 reflected in real-word repetition of polysyllables was a better predictor for receptive and expressive vocabulary development at Time 2 than picture naming of mono- and disyllabic words, and conversely receptive vocabulary at Time 1 was a predictor for phonological development at Time 2 while expressive vocabulary at Time 1 was not. This suggests that it is the formation of phonological representations, driving phonological differentiation in the mental lexicon, and not practice in word production, that facilitates increased phonological accuracy. Further research may explore the roles of phonological and cognitive-linguistic processing skills including working memory.