Influence of phonological development and input on first words – PREMS

As frequently described, child’s early productive lexicon is quantitatively and qualitatively very different from the adult language. Between 1 and 3 years-old, his/her lexicon is particularly limited and his/her first word production can be very far from the adult target. Several factors influence quantitative and qualitative development of first word production. Among them, two factors were frequently taken into consideration: phonetic/phonological development and input characteristics.
In this project on lexical development in toddlers, we will consider the interface between production and perception. Lexical acquisition will be viewed as emerging from motor capacities interactive with learning from the input language. The main goal of this project is to consider simultaneously the influence of articulatory constraints and input characteristics on lexical choice and lexical realization in young children before the 50-word-stage and after the 50-word-stage in a crosslinguistic perspective.
All the studies show how phonetics and phonology influences word selection (selectivity bias) and word productions (articulatory filter). Several characteristics of input have also been considered as factors influencing lexical acquisition. Even if most of the research conducted to date provides only indirect forms of evidence for evaluation of the effect of input on vocabulary acquisition, there appears to be also a general theoretical consensus on the positive effect of input on word learning.
Only very few studies have considered both factors simultaneously on the same subjects. Considering both factors at the same time will allow to measure the weight of each factor on first word production as well as to observe possible interactions between phonetic/phonological developments and input on first word production. In the proposed study children’s productions will systematically compared with adult language and child directed speech (CDS). In our study, influence of phonological development and input will be observed according to the linguistic stages of children between 12 and 30 months: before 50 words and after 50 words (i.e. before and after the lexical spurt). Finally, we will adopt a crosslinguistic comparison in order to see if observed processes are limited to one language only or if it’s possible to generalize the results to more than one language and particularly to languages from different language families. Among the four languages we have chosen to consider, two are quite often described (French and American English) and two have never been studied in the perspective of first word production (Tunisian Arabic and Tachelhit).
We intend to answer the following questions: does phonetic/phonological development influence lexical acquisition? Do input characteristics influence lexical acquisition? Does one have more weight than the other one? If the first three questions are right is it true through ages, at the beginning of first word as well as at the beginning of two words productions? Finally, does the answer to these questions is the same for all the languages under study?