Language Dimensionality and the Contribution of Cognitive Abilities on Verbal Repetition Tasks Performance in Spanish-English Bilingual Children with and without Developmental Language Disorders

Purpose: In the first study, we explored the dimensionality of language abilities in bilingual children using measures of vocabulary and morphosyntax in English and Spanish used clinically to identify bilingual children with DLD. In the second study, we look at selected cognitive processing skills to better understand their unique contribution to performance in verbal repetition tasks (sentence repetition and nonword repetition), which are frequently part of standardized language assessments for the diagnosis of DLD.

Method: Participants included 112 Spanish-English bilingual children ages 4-8 from a wide range of language abilities and language dominance profiles. Participants completed a battery of cognitive assessments and language assessments in Spanish and English. The cognitive session included general measures of cognitive abilities (nonverbal IQ and processing speed), short-term memory and working memory, cognitive flexibility, and inhibitory/attentional control. The language sessions included measures of vocabulary and morphosyntax from both norm-referenced assessments and language samples.

Results: In the first study, the model which best fit the data was a model with two correlated factors, one for Spanish and one for English. This model used a subset of the observed measures from norm-referenced assessments and language samples representing vocabulary and morphosyntax in both languages. In the second study, results indicate that the strongest predictors for SR task are measures of language abilities and then measures of short-term memory. For NWR, the strongest predictors are measures of short-term memory and then measures of language ability.

Conclusions: These results indicate that the structure of language in bilinguals is different from that previously found in English monolingual children of similar ages. In contrast to the unidimensional structure found for English monolingual children, language in Spanish-English children seems to represent two related but distinct constructs that may be influenced differently by language ability and language experience. Our results for the second study suggest that the verbal repetition tasks have similar underlying mechanisms. Although the skills to reproduce sentences and nonwords may overlap, it is understood that sentence repetition requires more linguistic knowledge than nonword repetition to reproduce the complete syntactic structure required. Clarifying how language in bilinguals is conceptualized and impacted by the concurrent development of two languages is an area that requires further research. Understanding both the dimensionality of language in bilinguals and the contribution of cognitive processing skills to language abilities can further assist our knowledge of how language develops in bilingual children and how it is affected by internal cognitive abilities.