Structural complexity is negatively associated with brain activity: a novel multimodal test of compensation theories of aging

NEUROBIOLOGY OF AGING

卷:98

Article

McDonough, Ian M.¹  Madan, Christopher R.² 

[1] Univ Alabama, Dept Psychol, Tuscaloosa, AL 35487 USA

[2] Univ Nottingham, Sch Psychol, Nottingham, England

关键词: Aging;    Compensation;    Default mode network;    Episodic memory;    Fractal dimensionality;    fMRI;   

DOI  :  10.1016/j.neurobiolaging.2020.10.023

来源: Elsevier

【 摘 要 】

Fractal dimensionality (FD) measures the complexity within the folds and ridges of cortical and subcortical structures. We tested the degree that FD might provide a new perspective on the atrophy compensation hypothesis: age or disease-related atrophy causes a compensatory neural response in the form of increased brain activity in the prefrontal cortex to maintain cognition. Brain structural and functional data were collected from 63 middle-aged and older adults and 18 young-adult controls. Two distinct patterns of FD were found that separated cortical from subcortical structures. Subcortical FD was more strongly negatively correlated with age than cortical FD, and cortical FD was negatively associated with brain activity during memory retrieval in medial and lateral parietal cortices uniquely in middleaged and older adults. Multivariate analyses revealed that the lower FD/higher brain activity pattern was associated with poorer cognitiondpatterns not present in young adults, consistent with compensation. Bayesian analyses provide further evidence against the modal interpretation of the atrophy compensation hypothesis in the prefrontal cortexda key principle found in some neurocognitive theories of aging. (c) 2020 Elsevier Inc. All rights reserved.

【 授权许可】

Free