Final Activity Report Summary - ROPP (The Role of Production Practise in Language Development) The aim of this study was to assess the relative contributions of sensitivity to speech patterns, i.e. perception, and vocal practice, i.e. production, to later language development. We followed a group of 12 infants which were exposed to English only in the home from 10 to 25 months. At 10 months of age the children participated in a head-turn experiment in which they listened to lists of highly familiar or phonologically matched unfamiliar words. We expected children with a good intrinsic sensitivity to speech patterns to respond with greater attention to the familiar word lists, showing that they were already able to represent and recognise familiar sound sequences. From 11 months onwards we video-recorded and audio-recorded the children once or twice monthly in a naturalistic play interaction with a parent until each child produced 25 different words in a half-hour session (25 wp). We returned to test these children on their ability to repeat words and non-words, i.e. on their phonological memory, at 25 months. As expected, children who showed more attention to familiar words at 10 months also learned to produce words more rapidly, thus we observed an earlier age at 25wp, although the effect was only a tendency in the expected direction. Consistent vocal practice with at least two consonants, in babbling, was strongly and significantly correlated with age at production of the first referential word as well as with age at the first context-limited, i.e. routine-based, word. Referential words tended to rely more heavily on well-practiced consonants than on earlier learned pre-canonical sounds, whereas words embedded in routines or games relied on both types of sounds to the same extent. This suggested that well-practiced consonants provided more essential support for referential word learning. The preliminary analysis of phonological memory tests from nine children showed a moderate correlation with the 10-month perception measure, which supported the view that sensitivity to phonological patterns was a stable, intrinsic skill or trait. However, we also had preliminary evidence that phonological memory was affected by vocal practice and experience with language. These results were the first to indicate the complex nature of phonological memory, an intrinsic capacity which, however, was not isolated or modular but was enhanced by lexical and phonological learning. Thus, this study established the important role of production practice in infancy for both word learning and construction of phonological memory.
