Biology enters the scene: A new perspective on bilingualism, cognition and dementia

The question of whether bilingualism can influence cognitive functions in healthy ageing as well as in brain diseases is currently a topic of an intense debate. In a study published in this issue of the “Neurobiology of Ageing” Estanga et al are breaking new ground by combining cognitive and biological approaches. Based on the data from the Guipuzkoa Alzheimer Project, they report that, compared to monolinguals, early bilinguals are not only characterized by a better cognitive performance in several domains and a lower prevalence of Alzheimer’s Disease, but also by lower levels of t-tau in their CSF. We suggest that sustained activation of noradrenergic signaling pathways associated with bilingualism could provide a possible mechanism linking results of this study with previous observations of delayed onset of dementia in bilinguals.