title: Bilingualism, executive control, and age at diagnosis among people with early-stage Alzheimer's disease in Wales.
abstract: The observation of a bilingual advantage in executive control tasks involving inhibition and management of response conflict suggests that being bilingual might contribute to increased cognitive reserve. In support of this, recent evidence indicates that bilinguals develop Alzheimer's disease (AD) later than monolinguals, and may retain an advantage in performance on executive control tasks. We compared age at the time of receiving an AD diagnosis in bilingual Welsh/English speakers (n = 37) and monolingual English speakers (n = 49), and assessed the performance of bilinguals (n = 24) and monolinguals (n = 49) on a range of executive control tasks. There was a non-significant difference in age at the time of diagnosis, with bilinguals being on average 3 years older than monolinguals, but bilinguals were also significantly more cognitively impaired at the time of diagnosis. There were no significant differences between monolinguals and bilinguals in performance on executive function tests, but bilinguals appeared to show relative strengths in the domain of inhibition and response conflict. Bilingual Welsh/English speakers with AD do not show a clear advantage in executive function over monolingual English speakers, but may retain some benefits in inhibition and management of response conflict. There may be a delay in onset of AD in Welsh/English bilinguals, but if so, it is smaller than that found in some other clinical populations. In this Welsh sample, bilinguals with AD came to the attention of services later than monolinguals, and reasons for this pattern could be explored further.
authors.affiliation: Bangor University, UK.
authors.forename: Linda
authors.initials: L
authors.lastname: Clare
authors.affiliation: North Wales Organisation for Randomised Trials in Health, Bangor University, UK.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Whitaker
authors.affiliation: Rotman Research Institute, Toronto, ON, Canada.
authors.forename: Fergus I M
authors.initials: FI
authors.lastname: Craik
authors.affiliation: Rotman Research Institute, Toronto, ON, Canada.|York University, Toronto, ON, Canada.
authors.forename: Ellen
authors.initials: E
authors.lastname: Bialystok
authors.affiliation: Bangor University, UK.
authors.forename: Anthony
authors.initials: A
authors.lastname: Martyr
authors.affiliation: Bangor University, UK.|National Institute for Social Care and Health Research Clinical Research Centre, North Wales Research Network, Bangor, UK.
authors.forename: Pamela A
authors.initials: PA
authors.lastname: Martin-Forbes
authors.affiliation: North Wales Organisation for Randomised Trials in Health, Bangor University, UK.
authors.forename: Alexandra J M
authors.initials: AJ
authors.lastname: Bastable
authors.affiliation: Bangor University, UK.
authors.forename: Kirstie L
authors.initials: KL
authors.lastname: Pye
authors.affiliation: Bangor University, UK.
authors.forename: Catherine
authors.initials: C
authors.lastname: Quinn
authors.affiliation: Bangor University, UK.
authors.forename: Enlli M
authors.initials: EM
authors.lastname: Thomas
authors.affiliation: Florida International University, Miami, FL, USA.
authors.forename: Virginia C Mueller
authors.initials: VC
authors.lastname: Gathercole
authors.affiliation: Bangor University, UK.|Betsi Cadwaladr University Health Board, Llandudno Hospital, Conwy, UK.
authors.forename: John V
authors.initials: JV
authors.lastname: Hindle
mesh_terms: D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D000544:Alzheimer Disease / Q000150:complications / Q000453:epidemiology / Q000523:psychology; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D056344:Executive Function / Q000502:physiology*; D005260:Female; D006801:Humans; D007807:Language Tests; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D019303:Multilingualism; D009483:Neuropsychological Tests; D018709:Statistics, Nonparametric; D014852:Wales / Q000453:epidemiology
keywords: cognitive reserve; inhibition; response conflict