Study establishes structure-function-cognition associations across the lifespan

MRI of brains

New research from the Center for Vital Longevity demonstrates that aging affects both the white matter connections between brain regions and brain activity. And importantly, that age-related reductions in these structural and functional aspects of the brain have negative cognitive consequences.

The findings, published in the March 30, 2020, issue of the journal Cerebral Cortex, suggest that reductions in the ability to regulate brain activity in response to increasing cognitive challenge negatively affect our cognitive performance. The findings also suggest that this is partly a result of age-related disruption to the white matter connections between gray matter regions.

“This appears to be a process that occurs even in healthy aging, highlighting the need to determine factors that help sustain both structural and functional brain health.”

Dr. Christina Webb, lead author of the research and a post-doctoral scientist at the CVL

The research was conducted as part of a large study supported by grants from the National Institutes of Health to Dr. Kristen Kennedy, and Dr. Karen Rodrigue, Associate Professors of Behavioral and Brain Sciences at The University of Texas at Dallas’ Center for Vital Longevity.

Structural equation modeling – a technique designed to test these associations – was used to test how these aspects of the brain and its performance were related. Participants (171 healthy adults ages 20-94) underwent magnetic resonance imaging (MRI) scanning including diffusion-weighted imaging (for tracking white matter connections) and functional imaging (to detect brain activity during performance of a task).

The model demonstrated that older age negatively affects task accuracy and other cognitive abilities more generally, in part due to both degraded white matter tract microstructure and reduced sensitivity of brain activity to task difficulty.

This structure-function association study provides further evidence that maintenance of our white matter connections as we age beneficially influences brain function, and the two mechanisms in tandem predict our cognitive performance as we age.

“These findings are important because traditionally these three aspects are studied separately (connectivity, functional activity, cognition), but only their combined study can help unravel their associations,” says Kennedy.

In addition to Kennedy, Rodrigue, and Webb, other authors of the paper from the CVL include Dr. Chris Foster, post-doctoral scientist, and David Hoagey, doctoral student.