Beyond the bilingual disadvantage: language dominance and word retrieval strategies in bimodal bilinguals' letter fluency

Aims and Objectives: Although bilingualism and its effects on cognition and language processing are widely studied, when it comes to bilingualism across modalities the current understanding is limited. Here we report a letter fluency task that compared word retrieval outcomes and strategies in early bimodal bilinguals (Czech and Czech sign language) and monolinguals (Czech). Methodology: Bimodal bilinguals (n = 15) and monolinguals (n = 15) matched for age, gender, and education completed a letter fluency task. Bimodal bilinguals’ language dominance was assessed by the gradient Bilingual Dominance Scale. The number of correctly retrieved words was analyzed, along with phonetic and semantic clustering, word corpus frequencies, errors, and retrieval failure durations.Data and Analysis: Data were analyzed using mixed-effects models. In addition to the most common analysis of the number of retrieved words, we ran a series of subsequent models to compare various aspects of the bimodal bilinguals’ and monolinguals’ word-retrieval strategies and mechanisms.Findings: The results showed that bimodal bilinguals retrieved fewer words than monolinguals and the number of correctly retrieved words was positively correlated with their self-reported bilingual dominance score in spoken Czech. As for the retrieval strategies in the two groups, our exploratory analyses of phonetic and semantic clustering and word corpus frequencies did not reveal significant effects of language background, although bimodal bilinguals tended to have longer stretches of silence between the retrieved words.Originality: The experiment studies lexical retrieval in an under-researched language landscape, namely in Czech and Czech sign language bilinguals. It is one of the first studies that explores clustering strategies in bimodal bilinguals vs. monolinguals and that reports an effect of language dominance in bimodal bilinguals’ verbal fluency.Implications: The present results suggest that retrieval difficulties in bimodal bilinguals are not solely due to phonological competition but may be influenced by cognitive trade-offs. Future research should consider not only linguistic factors but also personal traits and communicative styles shaped by the unique cultural experiences of bimodal bilinguals.KEYWORDS: bimodal bilingualism, letter fluency, lexical retrieval, language dominance, hearing children of deaf adults, CODA