Distinct structural correlates of the dominant and nondominant languages in bilinguals with Alzheimer's disease (AD)

Publication date: Available online 1 July 2019Source: NeuropsychologiaAuthor(s): Denis S. Smirnov, Alena Stasenko, David P. Salmon, Douglas Galasko, James B. Brewer, Tamar H. GollanAbstractStructural adaptations in brain regions involved in domain-general cognitive control are associated with life-long bilingualism and may contribute to the executive function advantage of bilinguals over monolinguals. To the degree that these adaptations support bilingualism, their disruption by Alzheimer's disease (AD) may compromise the ability to maintain proficiency in two languages, particularly in the less proficient, or nondominant, language that has greater control demands. The present study assessed this possibility in Spanish-English bilinguals with AD (n = 21) and cognitively normal controls (n = 30) by examining the brain correlates of dominant versus nondominant language performance on the Multilingual Naming Test (MINT), adjusting for age and education. There were no significant structural correlates of naming performance for either language in controls. In patients with AD, dominant language MINT performance was associated with cortical thickness of the entorhinal cortex and middle temporal gyrus, consistent with previous findings of temporal atrophy and related decline of naming abilities in AD. Nondominant language MINT performance, in contrast, was correlated with thickness of the left caudal anterior cingulate cortex (ACC), a central cognitive control region involve...

Source: Neuropsychologia - July 1, 2019 Category: Neurology Source Type: research