BILINGUALPLAS · Neurophysiological correlates of bilingual advantage and its contribution to cognitive reserve

Neurophysiological correlates of bilingual advantage and its contribution to cognitive reserve

In the last years, a hot topic in cognitive neuroscience is whether bilingualism contributes to improve executive functions (a set of cognitive processes such as ability to inhibit irrelevant information, switch attention between different stimuli, which are crucial to monitor goal directed actions) and increases cognitive reserve (CR, which involves optimised brain functioning). There are researchers stating evidence for bilingualism as a factor associated with enhanced executive functions and CR. However, a substantial number of studies failed to replicate enhanced executive functions in bilinguals compared to monolinguals. These results led to some authors to argue against the existence of a relationship between bilingualism, executive functioning and CR. Clarifying whether bilingualism contributes to improve executive functions and CR is highly important because a great amount of research has evidenced that high level of CR is related to greater resistance against brain damage. For instance, several studies found that Alzheimer’s disease symptoms could be delayed for five years in high compared to low CR persons, which would help to keep quality of life in older adults and maintain the sustainability of public health systems. There are a set of variables such as task difficulty and modality (i.e., visual vs. auditory tasks) as well as the presence of other CR factors in older adults, which could mask the existence of a bilingual advantage in executive functions. Thus, the main objective of the present research is systematically manipulating task difficulty (low vs. high), task modality (auditory vs. visual) and CR of the recruited participants (that is, we recruited low CR monolinguals, low CR bilinguals, high CR monolinguals, and high CR bilinguals) to examine whether auditory tasks with high difficulty level are more sensitive to enhanced executive functions in older adults bilinguals compared to monolinguals. Another main hypothesis of this research is that differences between monolinguals and bilinguals will appear in samples with low CR but not in samples of participants with high CR since other CR factors such as high education level and occupational status will be able to preserve executive functions regardless the number of spoken languages. As differences in neural processing may be not always evident at the behavioural level, we focused on behavioural and neurophysiological measures by means of electroencephalography (EEG) / event-related brain potentials (ERP) and magnetic resonance imaging (MRI).

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз