Age-related differences in the structural and effective connectivity of cognitive control: a combined fMRI and DTI study of mental arithmetic

• Published in: Neurobiology of aging Vol. 82; pp. 30 - 39
• Main Authors: Hinault, Thomas, Larcher, Kevin, Bherer, Louis, Courtney, Susan M., Dagher, Alain
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.2019
• Subjects: Aging; Arithmetic; Cognitive control; Connectivity; DTI; fMRI; Aging; DTI; fMRI; Connectivity; Cognitive control; Arithmetic
• ISSN: 0197-4580; 1558-1497
• DOI: 10.1016/j.neurobiolaging.2019.06.013

Cognitive changes with aging are highly variable across individuals. This study investigated whether cognitive control performance might depend on preservation of structural and effective connectivity in older individuals. Specifically, we tested inhibition following working memory (WM) updating and maintenance. We analyzed diffusion tensor imaging and functional magnetic resonance imaging data in thirty-four young adults and thirty-four older adults, who performed an arithmetic verification task during functional magnetic resonance imaging. Results revealed larger arithmetic interference in older adults relative to young adults after WM updating, whereas both groups showed similar interference after WM maintenance. In both groups, arithmetic interference was associated with larger activations and stronger effective connectivity among bilateral anterior cingulate, bilateral inferior frontal gyrus, and left angular gyrus, with larger activations of frontal regions in older adults than in younger adults. In older adults, preservation of frontoparietal structural microstructure, especially involving the inferior frontaloccipital fasciculus, was associated with reduced interference, and stronger task-related effective connectivity. These results highlight how both structural and functional changes in the cognitive control network contribute to individual variability in performance during aging. •We studied aging effects on the facilitation of inhibition after rule updating.•Diffusion tensor imaging and functional magnetic resonance imaging were used to assess functional and structural connectivity.•Reduced facilitation and larger frontal activation were observed in older adults.•Preservation of frontoparietal connectivity was associated with performance.•Connectivity changes contribute to the interindividual variability during aging.