Influence of structural and functional brain connectivity on age-related differences in fluid cognition

Neurobiol Aging. 2020 Dec;96:205-222. doi: 10.1016/j.neurobiolaging.2020.09.010. Epub 2020 Sep 12.

Abstract

We used graph theoretical measures to investigate the hypothesis that structural brain connectivity constrains the influence of functional connectivity on the relation between age and fluid cognition. Across 143 healthy, community-dwelling adults 19-79 years of age, we estimated structural network properties from diffusion-weighted imaging and functional network properties from resting-state functional magnetic resonance imaging. We confirmed previous reports of age-related decline in the strength and efficiency of structural networks, as well as in the connectivity strength within and between structural network modules. Functional networks, in contrast, exhibited age-related decline only in system segregation, a measure of the distinctiveness among network modules. Aging was associated with decline in a composite measure of fluid cognition, particularly tests of executive function. Functional system segregation was a significant mediator of age-related decline in executive function. Structural network properties did not directly influence the age-related decline in functional system segregation. The raw correlational data underlying the graph theoretical measures indicated that structural connectivity exerts a limited constraint on age-related decline in functional connectivity.

Keywords: Brain connectome; Executive function; Graph theory; Magnetic resonance imaging; Statistical mediation; System segregation.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Aged
  • Aging / pathology
  • Aging / psychology*
  • Brain / diagnostic imaging
  • Brain / pathology
  • Brain / physiopathology*
  • Cognition*
  • Connectome*
  • Diffusion Magnetic Resonance Imaging
  • Executive Function*
  • Female
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Nerve Net / diagnostic imaging
  • Nerve Net / physiopathology
  • Rest / physiology
  • Young Adult