Bilingualism, executive control, and age at diagnosis among people with early-stage Alzheimer's disease in Wales.

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.

Does language dominance affect cognitive performance in bilinguals? Lifespan evidence from preschoolers through older adults on card sorting, Simon, and metalinguistic tasks.

This study explores the extent to which a bilingual advantage can be observed for three tasks in an established population of fully fluent bilinguals from childhood through adulthood. Welsh-English simultaneous and early sequential bilinguals, as well as English monolinguals, aged 3 years through older adults, were tested on three sets of cognitive and executive function tasks. Bilinguals were Welsh-dominant, balanced, or English-dominant, with only Welsh, Welsh and English, or only English at home. Card sorting, Simon, and a metalinguistic judgment task (650, 557, and 354 participants, respectively) reveal little support for a bilingual advantage, either in relation to control or globally. Primarily there is no difference in performance across groups, but there is occasionally better performance by monolinguals or persons dominant in the language being tested, and in one case-in one condition and in one age group-lower performance by the monolinguals. The lack of evidence for a bilingual advantage in these simultaneous and early sequential bilinguals suggests the need for much closer scrutiny of what type of bilingual might demonstrate the reported effects, under what conditions, and why.

The Linguistic Mass/Count Distinction as an Indicator of Referent Categorization in Monolingual and Bilingual Children.

This study examines the acquisition of the linguistic mass/count distinction in English by bilingual (Spanish-English) children. The goal of the study is to explore whether bilingual children, like their monolingual peers, can draw information from the linguistic context in which a new noun id presented to determine whether the new word refers to an object or a substance. Results indicate that at 7 years of age, even bilinguals who are strong in English do not yet draw such inferences. By 9 years of age, however, bilinguals who are strong in English have response patterns similar to those of their monolingual peers but bilinguals who have lower English abilities still lag behind their monolingual peers in drawing such inferences.