The roles of cognitive control and language proficiency in bilingual language switching

Thematic Section: Language proficiency measures – what exactly are we measuring?

language-proficiency, language-dominance, cognitive-linguistic demands, bilingual-experience

Lia Pazuelo, The Graduate Center of the City University of New York
Thorfun Gehebe, The Graduate Center of the City University of New York
Rula Faour, The Graduate Center of the City University of New York
Klara Marton, City University of New York & ELTE

Bilingual individuals utilize cognitive control (CC) – monitoring, switching, and suppressing their languages – on a daily basis (Abutalebi & Green, 2007). Language-switching has been extensively studied in the bilingualism literature, including studies that compared language and non-linguistic task switching (e.g., Calabria et al., 2012) and those that used language-switching as a measure of language proficiency (e.g., Vivas et al., 2017).
The aim of this study was to examine the roles of language proficiency and CC in language-switching. This study is ongoing and the following results are based on 23 Thai-English, 4-6 years old children’s performances. The switching task included mixed blocks with a light-switching condition, where the stay-trials were more frequent than the switch-trials, therefore the task required more CC; and a dense-switching condition (more frequent switch-trials), where language-switching was more automatic.
Language proficiency was measured with the Language Experience and Proficiency Questionnaire (LEAP-Q; Marian et al., 2007) and the Cross-linguistic Lexical Tasks (CLT; Haman et al., 2017).
Linear mixed-effects regression analysis revealed a three-way interaction between switching frequency X language X trial type (p<0.01). This result indicated that the switching effect was larger in the light-switching condition that required more CC than in the dense-switching condition, that required less control. Further, the role of language proficiency in language-switching was supported by a moderate correlation between the switch-cost in the light-switching condition for Thai and the Thai CLT scores (rs =0.52,p<0.05), suggesting that children who performed better on the vocabulary task also performed faster on the stay trials during the light-switching condition that resulted in a higher switch-cost. These findings indicate that language-switching involves multiple processes and is highly demanding on both CC and language proficiency.