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

NEUROPSYCHOLOGIA

卷:132

Article

Smirnov, Denis S.¹  Stasenko, Alena^2,3  Salmon, David P.¹  Galasko, Douglas¹  Brewer, James B.¹  Gollan, Tamar H.³ 

[1] Univ Calif San Diego, Dept Neurosci, Shiley Marcos Alzheimers Dis Res Ctr, La Jolla, CA 92093 USA

[2] San Diego State Univ, San Diego Joint Doctoral Program Clin Psychol, Univ Calif San Diego, San Diego, CA 92182 USA

[3] Univ Calif San Diego, Dept Psychiat, La Jolla, CA 92093 USA

关键词: Bilingualism;    Cognitive control;    Alzheimer's disease;    Structural neuroimaging;    Anterior cingulate cortex;   

DOI  :  10.1016/j.neuropsychologia.2019.107131

来源: Elsevier

【 摘 要 】

Structural 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 involved in error monitoring and task switching. The relationship between naming in the nondominant language and ACC in patients with AD but not in controls may reflect increased reliance on the ACC for nondominant language use in the face of atrophy of other control network components. The results are consistent with the possibility that the increased burden nondominant language use places on cognitive control systems compromised in AD may account for faster nondominant than dominant language decline in AD.

【 授权许可】

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