Slide Slam L2
Effects of bilingual experience on oscillatory dynamics in inhibition
Sergio Miguel Pereira Soares1, Yanina Prystauka2, Vincent DeLuca2, Jason Rothman2,3; 1University of Konstanz, 2UiT The Arctic University of Norway, 3Nebrija University
At least under specific conditions of individual-level experience/engagement with bilingual language exposure and use, managing multiple languages can lead to structural and functional adaptations in the brain. However, the effects of bilingualism on the neural underpinnings of executive function (EF) remain understudied. Research using time-frequency representations (TFRs) has shown that EF tasks (e.g. Flanker task) modulate power within theta- and alpha frequency bands. These power modulations have been linked to a greater engagement of the executive control system (Cavanagh & Frank, 2014; Suzuki et al., 2018). Herein, we use EEG with a Flanker task to investigate how individual differences in language experience may modulate neurocognitive outcomes (specifically oscillatory dynamics). EEG and behavioral data were collected from 60 bilinguals (28 early bilinguals; 32 late-acquired L2 learners). Participants also completed the Language and Social Background Questionnaire (LSBQ; Anderson et al., 2018). TFRs were computed for both the incongruent- and congruent trials, and the difference between the two (Flanker effect vis-à-vis cognitive interference) was then 1) compared between the early- and later acquired bilinguals (via cluster-based permutations analysis) and 2) modeled as a function of individual differences in language experience using continuous measures of bilingualism derived from the LSBQ. At the group level, we predicted greater brain engagement in early compared to late bilinguals, specifically increased theta activation followed by alpha suppression for the Flanker effect. Furthermore, we hypothesized degree of active bilingualism would predict changes in alpha and beta bands in both early and late bilinguals. Finally, we predicted a correlation between reaction times (RTs) and power modulation within the alpha- and theta bands. Incongruent trials incurred significantly slower RTs than congruent trials, higher theta power in central electrodes 300-600ms post-stimulus onset, and decreased alpha power in centro-parietal electrodes 600-950ms post-stimulus onset. No significant differences were observed between groups for either behavioural or neural responses. However, individual differences analyses revealed significant correlations between age, age of acquisition, and usage of the non-societal language at home with alpha and beta band activity for late bilinguals, whereas only age effects were found in early bilinguals. Furthermore, when correlating alpha power with RTs, early bilinguals showed a negative correlation while later bilinguals show a positive correlation. Taken together, the results indicate adaptations towards differential brain recruitment to deal with the cognitive demands associated with variation in language experience. References Anderson, J. A., Mak, L., Chahi, A. K., & Bialystok, E. (2018). The language and social background questionnaire: Assessing degree of bilingualism in a diverse population. Behavior Research Methods, 50(1), 250–263. Cavanagh, J. F., & Frank, M. J. (2014). Frontal theta as a mechanism for cognitive control. Trends in Cognitive Sciences, 18(8), 414–421. Suzuki, K., Okumura, Y., Kita, Y., Oi, Y., Shinoda, H., & Inagaki, M. (2018). The relationship between the superior frontal cortex and alpha oscillation in a flanker task: Simultaneous recording of electroencephalogram (EEG) and near infrared spectroscopy (NIRS). Neuroscience Research, 131, 30–35.