Bilingualism as a potential protective factor for cognition and language in brain tumor

Abstract

Bilingualism modulates structural and functional brain properties and hence sculpts cognition and language. The aim of this study was to evaluate whether this effect of bilingualism on cognition and language processing is preserved when a primary left-dominant hemisphere brain tumor is present. Results from a large sample of individuals ( n  = 119) showed higher performance of bilinguals in lexico-semantic, nonword repetition, verbal fluency and attention/short-term memory tasks at the presurgery assessment. The beneficial effect of bilingualism on semantic knowledge, nonword repetition and phonological verbal fluency was maintained regardless of the type of brain tumor, whereas the bilingual effect on semantic verbal fluency was influenced by the type of tumor. Moreover, the machine learning results indicated that the lexico-semantic association task was the best predictor of bilingualism. Our results provided the first evidence of bilingualism as a protective factor for cognition of patients with a brain tumor diagnosis, most probably for language-learning abilities.