Presentation

Toms Voits¹, Jubin Abutalebi^2,1, Vincent DeLuca¹, Jon Andoni Duñabeitia^3,1, Janine Rook⁴, Jason Rothman^1,3; ¹UiT the Arctic University of Norway, ²University Vita Salute San Raffaele, ³Universidad Nebrija, ⁴University of Groningen

At least under conditions of active engagement, multilingualism has been observed to affect brain structure and function across the lifespan (Bialystok, 2021). It has been associated with increases in compensatory mechanisms towards age-related neurocognitive decline, leading to a more favorable trajectory of cognitive aging (CA) (for review see Gallo et al., 2022). However, the majority of research examining effects of bi-/multilingualism on CA has typically operationalized bilingualism as a dichotomous variable, despite it being a heterogeneous individual experience (DeLuca et al., 2019). Furthermore, little of the relevant research has included middle-aged individuals, an important transitional period in the lifespan between peak cognition and older age where it becomes typically degraded. Thus, our understanding of how multilingualism affects the trajectory of neural decline across the adult lifespan is limited. Of course, multilingualism is not the only cognitively demanding activity in which individuals differentially engage: several other lifestyle factors have been found to affect the trajectory of CA (e.g., exercise, diet, education, etc). However, multilingualism has rarely been compared while accounting for these other factors to examine whether it independently contributes to resilience against symptoms of CA. The present study aimed to address these issues simultaneously by examining effects of multilingualism on CA across a large age range of adults while taking into account various other lifestyle factors. We used resting state electroencephalography (rs-EEG) as a measure of neurocognitive function. Specifically, rs-EEG coherence has been previously found to index increased reserve against CA (Fleck et al., 2017) and to be modulated by degree of engagement in bilingual experience in young adults (e.g., Pereira Soares et al., 2021). A cohort of multilingual native speakers of Norwegian with high proficiency in English, (preliminary analysis n = 20, projected n = 100; mage = 57.1, SD = 11.8, range 45-82) were administered a battery of demographic questionnaires tapping into bilingualism and various other lifestyle experiences. A rs-EEG recording was also taken. Continuous measures of multilingual engagement were calculated from the Language History Questionnaire 3.0 (Li et al., 2020), including a multilingual diversity score (MLD) which is based on the language entropy measure (e.g., Gullifer & Titone, 2019). Rs-EEG data were analyzed by calculating coherence between a series of electrode regions for a set of frequency bands (following Bice et al., 2019; Pereira Soares et al., 2021). Functional coherence measures were entered into linear regression models with the demographic variables. A base model first specified age and lifestyle scores as main effects. Follow-up models including interaction terms of MLD score with age were run and compared to the base models. Preliminary results showed significant interactions of MLD score and age on several coherence measures. Specifically, higher MLD scores corresponded to increased high-beta brain coherence between the anterior left and right electrode clusters (LFT and RFT) in more advanced age. The present pattern of results indicate that degree of multilingual engagement impacts functional coherence across the adult lifespan, and crucially appears to be an independent contributor to increased reserves against effects of CA.

Topic Areas: Multilingualism, Control, Selection, and Executive Processes