Effects of four-month-long foreign language learning on executive functions and white matter integrity in older adults

摘要: Bilingualism has been associated with cognitive benefits and a potential protective effect against neurodegenerative conditions. Previous research has shown that bilingual individuals exhibit greater white matter integrity compared to monolinguals of the same age. However, the impact of foreign-language learning on brain structure in older adults during the initial stages of language acquisition remains uncertain. This study aimed to investigate the cognitive and structural effects of a four-month-long foreign language learning program in a group of healthy older adult monolinguals. Thirteen Italian-speaking participants (aged 59-78) underwent a four-month intensive English course for beginners. Pre- and post-assessments were conducted to evaluate executive cognitive functions, as well as diffusion tensor imaging (DTI) to examine brain structural changes. The study findings showed substantial increases in axial, radial, and mean diffusivity during the four-month language learning period. The most prominent variations were observed in key brain regions, namely the fronto-occipital fasciculus, the superior longitudinal fasciculus, and the corpus callosum areas. Notably, brain-behaviour correlations indicated a robust positive relationship between changes in axial diffusivity and performance on the Stroop task, which assesses cognitive interference inhibition. These findings suggest that a four-month foreign language learning program can induce structural changes in the brain, particularly affecting white matter integrity, and that these structural changes are associated with improvements in executive functions. The study highlights the potential of …