Different structural brain patterns and their association with executive function and general cognitive ability in cognitively normal elderly adults

TL;DR

This study explores how brain structure differences in older adults relate to cognitive abilities like executive function and general cognition.

Contribution

The study identifies specific brain structural patterns in older adults and their links to cognitive functions.

Findings

Older adults showed reduced cortical thickness in frontal regions and gray matter volume in thalamus and putamen.

Right thalamus gray matter volume is significantly associated with executive function in older adults.

Executive function mediates the relationship between brain structure and cognition in younger but not older adults.

Abstract

Structural gray matter changes were significantly observed in cognitively normal elderly adults, but the associations between different structural brain patterns, executive function, and general cognitive ability in older adults have not been fully explored.

A total of 119 cognitively normal elderly adults and 162 healthy younger adults were enrolled in this study and underwent extensive cognitive assessment and structural magnetic resonance imaging. Surface-based morphometry was used to reconstruct the cortical surface and derive structural indices, including cortical thickness (CT), surface area (CSA), and gray matter volume (GMV), which were then used to examine brain region differences between younger and older adults. Moderated mediation model analysis was conducted to explore the associations between different structural brain patterns, executive function, and general cognitive ability.

Compared with younger adults, older adults showed significantly lower CT mainly in frontal regions and lower GMV of bilateral thalamus and bilateral putamen. The analysis of the mediating effect found that the GMV of the right thalamus is significantly associated with executive function, and executive function is also significantly associated with general cognitive ability. Furthermore, for younger adults, executive function mediated the effect of GMV of the right thalamus on general cognitive ability, whereas for older adults, the mediating effect of executive function was not significant.

Cognitively normal elderly adults exhibited different structural brain patterns, which were further associated with executive function and general cognitive ability. These findings shed light on the relationship between brain structural pattern changes and cognition in cognitively normal elderly adults.

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