The association between multilingual experience factors and cognitive functioning in older adults: A Lifelines study

Objectives: The complex life experience of speaking two or more languages has been suggested to preserve cognition in older adulthood. This study aimed to investigate this further by examining the relationship between -multilingual experience variables and cognitive functioning in a large cohort of older adults in the diversely multilingual north of the Netherlands.
Method: 11,332 older individuals participating in the Lifelines Cohort Study completed a language experience questionnaire. From this cohort, a subset was selected (n = 3,972, aged 59-86) for whom complete demographic and cognitive data were available and who had learned at least two languages to evaluate the association between multilingual experience variables and cognitive functioning. Cognitive functioning was assessed using the Cogstate Brief Battery, which measures processing speed, attention, working memory, and recognition memory. 
Results: A linear regression analysis revealed that a higher number of languages learned was related to better performance on all subtasks. In addition, a later onset of acquisition of the second language (L2) was associated with better attention. These effects were independent of demographic variables such as age, education level, income level, and country of birth.
Discussion: The results demonstrate that in our cohort only the -experience- factors of the number of languages learned and L2 onset of acquisition related to cognitive functioning. Our evidence supports the idea that there is a positive relationship between multilingual experiences and cognitive functioning in older adulthood, but more longitudinal work is needed to establish whether learning multiple languages can potentially promote healthy aging.
Keywords: multilingualism, multilingual experience, cognition, population-based cohort study