Effects of bilingualism on the age of onset and progression of MCI and AD: evidence from executive function tests.
Previous articles have reported that bilingualism is associated with a substantial delay in the onset of both Alzheimer's disease (AD) and Mild Cognitive Impairment (MCI). The present study reports results from 74 MCI patients and 75 AD patients; approximately half of the patients in each group were bilingual. All patients were interviewed to obtain details of their language use, onset of their condition, and lifestyle habits. Patients performed three executive function (EF) tests from the D-KEFS battery (Trails, Color-Word Interference, Verbal Fluency) on 3 occasions over a period of approximately 1 year. Results replicated the finding that bilingual patients are several years older than comparable monolinguals at both age of symptom onset and date of first clinic visit. This result could not be attributed to language group differences in such lifestyle variables as diet, smoking, alcohol consumption, physical activity, or social activity. On the first testing occasion, performance on the EF tasks was generally comparable between the language groups, contesting arguments that bilinguals wait longer before attending the clinic. Finally, EF performance tended to decline over the 3 sessions, but no differences were found between monolinguals and bilinguals in the rate of decline.
Department of Psychology, York University.
Ellen
E
Bialystok
Rotman Research Institute at Baycrest.
Fergus I M
0000-0001-8073-3236
FIM
Craik
Rotman Research Institute at Baycrest.
Malcolm A
MA
Binns
Department of Psychology, University of Michigan.
Lynn
L
Ossher
Rotman Research Institute at Baycrest.
Morris
M
Freedman
D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000453:epidemiology*; D060825:Cognitive Dysfunction / Q000453:epidemiology*; D018450:Disease Progression; D056344:Executive Function; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019303:Multilingualism; D009483:Neuropsychological Tests