Publication Type: Individual Poster
Abstract: Background and Aims: It has been shown that that children’s ability to repeat sound patterns relates to their vocabulary size (Gathercole & Baddeley, 1989; Sato et al., 2005). Especially, performance of non-word repetition at the age of four provides a good prediction of vocabulary size at the age of five. Masur (1995) reported that verbal imitation of real words at the age of 13 months predicts vocabulary development a half year later. However, there is a gap in methodology between the study of one-year-olds and those of children 3 years and up. In this study, we applied the procedure of studies of older children to 2-year-old children and explored the following points: (1) whether the ability of non-word repetition develops at 2 years of age, (2) whether 2-year-old children’s performance of non-word repetition relates to their vocabulary size and whether the mothers’ interaction with their children fosters their repetition skill.

Methods: Participants were Japanese-learning children (21-25 months). We measured their phonological loop ability by using a non-word repetition task and their vocabulary development with the MacArthur CDI (Japanese version). In the non-word repetition task, mothers pronounced 10 four-mora/four-syllable non-words (e.g. nebunebu) and asked their children to repeat the non-words. The task was conducted twice with a two-week interval for each child. The children’s responses were recorded with video cameras and were transcribed by two coders. Incomplete imitation of a presented non-word scored ‘1’, correctly imitated non-words scored ‘2’.

Key results: The children’s performance of the non-word repetition related to their vocabulary size and their chronological age. Children with a large vocabulary performed better than the others, and 25-month-old infants did better in the repetition task than 21-month-olds. In addition, children with a vocabulary of over 200 words correctly repeated at least three times, whereas those under 200 words never succeeded. Social interaction from mothers also related to their children’s performance.

Conclusions: The results suggest: (1) the ability of non-word repetition would develop at around 2 years of age after children acquire more than 200 words, (2) the performance of non-word repetition relates to vocabulary development at 2 years of age, and mothers’ interaction with their children facilitates their repetition skill.