Early lexical and phonological acquisition and its relationships

The impact of enhanced Milieu teaching with phonological emphasis (EMT + PE) on the speech and language outcomes for toddlers with cleft palate in Brazil and the United States of America

PURPOSE

The purpose of this study was to compare the speech and language outcomes of children with cleft palate with or without cleft lip (CP+/-L) in the USA to children with CP+/-L in Brazil who underwent intervention with enhanced Milieu teaching with phonological emphasis (EMT + PE), as there are few cross-country intervention comparisons for children with CP+/-L.

METHOD

This is a retrospective analysis of 29 participants from the USA and 24 participants from Brazil who were matched on age. The US participants were between the ages of 13-35 months (M = 23.76), spoke Standard American English in the home, and were recruited from East Tennessee State University and Vanderbilt University. The Brazilian participants were between the ages of 20-34 months (M = 25.04), spoke Brazilian Portuguese in the home, and were recruited from the Hospital de Reabilitação de Anomalias Craniofaciais-Universidade de São Paulo. All treatment participants received EMT + PE from trained speech-language pathologists in hospital-university clinics.

RESULT

The treatment groups demonstrated greater gains than comparison groups in percent consonants correct, number of different words, and expressive/receptive vocabulary. There was no main effect nor interaction by country.

CONCLUSION

The application of EMT + PE in a second culture and language is a viable early intervention option for participants with CP+/-L.

Multiplex lexical networks reveal patterns in early word acquisition in children

Network models of language have provided a way of linking cognitive processes to language structure. However, current approaches focus only on one linguistic relationship at a time, missing the complex multi-relational nature of language. In this work, we overcome this limitation by modelling the mental lexicon of English-speaking toddlers as a multiplex lexical network, i.e. a multi-layered network where N = 529 words/nodes are connected according to four relationship: (i) free association, (ii) feature sharing, (iii) co-occurrence, and (iv) phonological similarity. We investigate the topology of the resulting multiplex and then proceed to evaluate single layers and the full multiplex structure on their ability to predict empirically observed age of acquisition data of English speaking toddlers. We find that the multiplex topology is an important proxy of the cognitive processes of acquisition, capable of capturing emergent lexicon structure. In fact, we show that the multiplex structure is fundamentally more powerful than individual layers in predicting the ordering with which words are acquired. Furthermore, multiplex analysis allows for a quantification of distinct phases of lexical acquisition in early learners: while initially all the multiplex layers contribute to word learning, after about month 23 free associations take the lead in driving word acquisition.