Exploring the Relationships Between Sleep Quality, Multilingual Proficiency and Working Memory in Young Adults

Aims and Objectives/Purpose/Research Questions: This exploratory study examines whether sleep quality moderates the relationship between balanced multilingual proficiency and working memory (WM) in U.K.-based young adults speaking two or more languages. Design/Methodology/Approach: Using a cross-sectional design, 91 multilingual U.K.-based young adults ( M age = 20.63) completed self-report measures of multilingual proficiency and sleep quality and two computerised WM tasks. Data and Analysis: Data were analysed using hierarchical regression to test main effects and PROCESS macro moderation analyses to examine interaction effects. Sensitivity of findings to model specification was also examined. Findings/Conclusions: No statistically significant evidence of sleep moderation was found, but smaller moderation effects cannot be excluded given limited power. Balanced multilingual proficiency was unrelated to verbal WM and had a small negative association with visuospatial WM in the primary analysis that weakened after excluding zero scorers. Poor sleep quality was associated with worse visuospatial WM in certain exploratory analyses. Originality: This is one of the first studies providing an exploratory investigation of sleep quality as a moderator of multilingualism-WM associations and highlighting methodological considerations about statistical sensitivity and WM task selection. Significance/Implications: These findings should be considered exploratory and hypothesis-generating and warrant sufficiently powered multilingualism studies using more sensitive WM measures.