Sooraj Shah ’24
Over 43% of the United States population is bilingual and speaks more than one language. A skill fostered at a young age, bilingual speakers can converse and switch freely between multiple languages, but the root cause of why and when this occurs is not clear. A study conducted in Spain in collaboration with Stony Brook University’s Psychology Department explored the relationship between the ability to switch languages and lexical access, which is the way individuals mentally access words from their vocabulary. Inhibition control, the ability to suppress natural instinct, was also studied in the context of choosing a language. Using experimental designs consisting of native speakers of two different languages and different picture naming trials, the difference in response times and preferred language were recorded and analyzed.
Data was collected from Basque and Spanish speaking individuals living in the Basque Country, a region in Northern Spain. The study was broken down into two groups, with 55 individuals in experiment 1 and 43 individuals in experiment 2. Experiment 1 consisted of a voluntary language switching task(VLST) in which participants were asked to name randomly ordered pictures in either Spanish or Basque. The VLST was further broken down into a “blocked” and “mixed” section in which only Spanish or Basque was used and in which the language used was decided by the participants respectively. In experiment 2, participants were cued to switch languages while naming the pictures rather than switching languages on their own. Both experiments also included background tasks and measurements of working memory and inhibitory control.
Experiment 1 yielded results which showed a mixing benefit for voluntary switching as performed in experiment 1. When participants were allowed to switch languages at their own leisure, response times were very minimal. Feasibility of lexical access was also supported in that responses were faster for easier words in the non-dominant language(in this case Basque) while harder words were reserved for the dominant language(in this case Spanish). Experiment 2’s results allowed for a comparison between cued and VLST. A mixing cost was experienced when participants were cued in, while a mixing benefit was experienced during VLST. This showed that lexical access was slightly more restricted when languages were forcibly switched. The results showed the relationship between lexical access and a bottom-up approach, where individuals resort to the dominant language for harder words, while simple vocabulary is supported by the non-dominant language. Top-Bottom processes on the other hand, may play a role during the blocked single language conditions as well as when the language was switched.
Understanding the neural activity transpiring within the switching of languages in daily life is dependent on lexical access as supported by the study. In addition, voluntarily using two languages may be less costly than using one language, contributing to why and when bilinguals switch languages. Future linguistic studies will focus further on cognitive decisions.
 A. de Bruin, A. G. Samuel, and J. A. Duñabeitia, Voluntary Language Switching: When and Why do Bilinguals Switch Between Their Languages? ScienceDirect 103, 28-43(2018). doi: https://doi.org/10.1016/j.jml.2018.07.005