Beyond Alzheimer’s Disease: Bilingualism and Other Types of Neurodegeneration

Abstract

Bilingualism has been argued to have an impact on cognition and brain structure. Such effects have been reported in healthy children and young adults, but also in ageing adults, including clinical ageing populations. For example, bilingualism may significantly contribute to the delaying of the expression of Alzheimer’s dementia symptoms. If bilingualism plays an ameliorative role against neurodegeneration, it is possible that it would have similar effects for other neurodegenerative disorders, including Multiple Sclerosis, Parkinson’s and Huntington’s Diseases; however, relevant evidence remains limited. Herein, we provide a focused literature review on the effects of these progressive neurological disorders on cognition and brain structure, examine how the affected functions and brain regions map to those suggested to be impacted by bilingualism, and report the limited evidence of the impact of bilingualism on these conditions. We then examine the value of making links across neurodegenerative disorders and bilingualism, proposing that available evidence warrants claims for bilingualism- related effects more generally, with an eye at future research to fill in gaps in our understanding.

The Many Shades of Bilingualism: Language Experiences Modulate Adaptations in Brain Structure

“…If bilingualism is shown to counteract cognitive and/or brain decline related to AD and MCI, it might be the case that its beneficial effects are not constrained to these diseases only, although other neurodegenerative disorders have hardly been studied in this context (Voits, Pliatsikas, Robson, & Rothman, ). For example, there are very few studies examining progressive neurodegeneration in diseases such as Huntington's and Parkinson's in connection with bilingualism.…”

The effects of bilingualism on the structure of the hippocampus and on memory performance in ageing bilinguals

“…Examining bilingualism as a continuous variable allows to account for within groups variability which may be lost in a more classically defined monolingual vs bilingual groups comparison (Leivada, Westergaard, Duñabeitia, & Rothman, 2020;Luk & Bialystok, 2013;Surrain & Luk, 2019). Moreover, focused studies similar to this one, are required with clinical populations too, to add to a small but growing literature that will help us better understand the potential clinical implications both in healthy and pathological ageing (Voits, Pliatsikas, Robson, & Rothman, 2019).…”