Experience-Related Differences on Attentional Control in Cognitive Ageing: An Investigation of Bilingualism Effects on Flanker Conflicts in TFRs

Abstract

Bilingualism has been argued to help maintain cognitive functioning in ageing by contributing to the cognitive reserve, the brain’s functional adaptability and resilience against cognitive decline. Within this, the constant engagement with bilingual mechanisms to monitor multiple languages arguably leads to neurocognitive adaptations of attentional systems. Examining bilingual experience as a spectrum, and how these potentially link to variable individual outcomes in cognitive ageing remains understudied. Therefore, this study investigates the effect of individual differences in bilingual experiences on neurocognition in middle-aged adults and seniors. In the study, a non-linguistic flanker task was implemented while measures of both indices of brain activity through EEG and behavioral data were collected. In looking at the relation between differences in bilingual experiences and ageing, the study found that more balanced bilinguals were able to maintain their reliance on alpha activity in ageing, associated to the efficiency of attentional resources to focus on task relevant stimuli. Furthermore, the study found indications of a post stimulus increase in theta power related to cognitive control recruitment. The behavioral findings however, showed the opposite pattern as to what was expected, as subjects with more engagement in bilingual experiences showed a bigger effect of age on flanker task reaction times. Overall, these findings indicate that individual differences in bilingual experiences have a modulatory effect on neurocognition in ageing, potentially leading to better maintained cognitive functioning in cognitive decline.