Alexandra Miles

Bilingualism has been positively related to the development of executive function, which refers to brain processes that control goal-oriented activities such as attention, planning, and self-control. While many factors such as level of fluency, education, and culture have been shown to influence this “bilingual advantage,” little is known about the impact of the language of test administration when measuring executive function in bilingual individuals. This study examined if bilingual young adults perform similarly on measures of executive function completed in their dominant and non-dominant languages. Participants consisted of 20 individuals between the ages of 18 and 25-years-old who self-reported at least an advanced level of fluency in English and in Spanish. Each participant completed questionnaires regarding their background demographics and language history, as well as a measure of their oral proficiency in English and Spanish. They then completed two executive function measures in English, and two in Spanish. The results show that bilingual people may experience more conflict in their native language on executive function measures involving language-based stimuli, meaning they slow down more on the task in their native language, z = 2.44, p = .015. However, when comparing performance in the dominant vs. non-dominant language, there is no significant difference. Instead, the difference in fluency levels is significantly related to the difference in performance between the two tasks, rs(18) = .46, p = .039. This suggests that both the native language and the levels of fluency may both be significant when considering the language of test administration for measures of executive function. Further research is needed to better understand how these potential differences develop, as well as their clinical implications.