A – 1 Bilingualism Serving as a Neuroprotective Factor for Processing Speed and Memory Abilities in Mexican Bilinguals with Alzheimer’s Disease

Abstract Objective We examined the influence of bilingualism on cognition in a Mexican population with and without Alzheimer’s disease (AD). Method Twenty-five healthy comparisons (HC; 11 Spanish monolinguals & 14 Spanish-English bilinguals), 40 persons with mild cognitive impairment (MCI; 16 Spanish monolinguals & 24 Spanish-English bilinguals), and 26 persons with AD (14 Spanish monolinguals & 12 Spanish-English bilinguals) completed language, processing speed, visual perception, executive functioning, and memory measures to evaluate cognition. A series of 3x2 ANCOVAs were conducted to determine main effects and interactions between bilingualism and AD on cognition. Bonferroni post hoc tests were used to evaluate significant differences between our groups. Results The AD group significantly underperformed across all cognitive domains in contrast to their counterparts. Next, bilinguals significantly demonstrated overall better cognitive abilities compared to monolinguals, except on one visual perception task. Conversely, interactions emerged where bilinguals with AD significantly demonstrated better processing speed (via Coding) and memory abilities (via California Verbal Learning Test) compared to monolinguals with AD. Finally, interactions also emerged where monolinguals with AD significantly demonstrated better processing speed (via Digit Span Forward), visual perception (via Visual Puzzles), and executive functioning abilities (via Matrix Reasoning) compared to bilinguals with AD. Conclusion Bilinguals with AD demonstrated better cognitive abilities on some cognitive domains compared to monolinguals with AD. Signifying that bilingualism could be serving as a neuroprotective factor in processing speed and memory abilities. Further exploration is needed with a bigger sample to examine how bilingualism could potentially be serving as a neuroprotective factor in Mexican bilinguals with AD.