title: Lexical/semantic organisation in bilingual and monolingual infants
Creators: name: Farag, Rafalla
Publisher: name: University of Plymouth
Year: 2013
Subjects: Bilingual children

description: Abstract Previous studies show that bilingual infants are slower in developing phonology and tend to experience some difficulties in acquiring some grammatical rules. Furthermore, as compared to their monolingual peers, bilingual infants tend to have less vocabulary. This thesis set out to explore how bilingual infants organise the lexical information in their two languages. Specifically, we examined the lexical-semantic relationships between words within and across languages using a word-to-word priming paradigm. The thesis sought also to uncover any relationship between semantic priming effects and the size of vocabulary. Vocabulary measures such as the BPVS II, the SETK, and the Oxford CDI were used in the experiments, along with an experimental design close to that used in Styles and Plunkett (2009) and Arias-Trejo and Plunkett’s (2009) studies, based on the Intermodal Preferential Looking (IPL) paradigm. The basic design was that the infants were presented with a prime word (e.g. ‘dog’) followed by a target word which was related either semantically to the prime (e.g. ‘cat’) or not (e.g. ‘bus’). Immediately thereafter, we presented two images, depicting the target and a distracter, and monitored the looking times towards the images. In Experiment 1, we tested whether upon hearing related prime and target words, as compared to unrelated pairs, 30 month old monolingual infants preferred to look at the target more than the distracter image. This constituted a benchmark priming effect. In Experiment 2, we examined whether the presence of the target word was necessary for a priming effect to occur. The results demonstrated an effect of semantic priming in the word-word condition (Exp.1) but no semantic priming effect was found in the word-image condition (Exp.2). Experiment 3 investigated, in each of their languages, the semantic priming effect in bilingual 30-month-olds (Arabic-English). The overall result revealed a significant semantic priming effect along with a different pattern in Arabic and English. Experiment 4 was designed to investigate, in a cross-linguistic design, semantic priming in bilingual 18-month-old infants and to address the symmetry between forward (L1-L2) and backward (L2-L1) priming. The overall results showed no semantic priming effect; however, infants showed a non-significant tendency for forward (L1-L2) over backward (L2-L1) priming. As controls for the previous experiments, in Experiments 5 and 6 we examined monolingual and bilingual 18-month-olds to explore whether a priming effect could be obtained only in English. The results showed no semantic priming effect and no strong evidence of a naming effect. All the findings suggested that hearing words activated automatically some other words which, in both monolingual and bilingual infants, were related semantically around 30 months of age, but were not found at 18 months in either population. Despite what is reported often about a delay of language in bilingual children, these findings suggest that, although they show a smaller size of vocabulary in each of their languages when compared to monolingual infants, bilingual infants may build the semantic relationship between words at the same time as their monolingual peers, and with similar word-to-word relations.