Changes in pairwise functional connectivity associated with changes in cognitive performance in cognitively normal...

Area of Science:

• Neuroscience
• Cognitive Aging
• Neuroimaging

Background:

• Cognitive decline in aging is a growing concern, with its neurobiological underpinnings in healthy individuals needing further elucidation.
• Resting-state functional magnetic resonance imaging (rs-fMRI) has been used to study brain function, but longitudinal changes require more investigation.

Purpose of the Study:

• To investigate two-year changes in functional brain connectivity among cognitively normal older adults.
• To explore the relationship between these longitudinal brain changes and cognitive performance shifts.
• To identify specific brain networks associated with cognitive changes over time.

Main Methods:

• Utilized resting-state functional magnetic resonance imaging (rs-fMRI) to assess functional connectivity.
• Analyzed changes in connectivity across 80 gray matter areas over a two-year period.
• Employed a cross-validated permutation variable importance measure to identify key features related to cognitive change.

Main Results:

• Identified eleven pairs of age-corrected functional connections as significant predictors of cognitive change.
• These significant connections were predominantly within the default mode network (DMN).
• A linear regression model with cross-validation achieved a mean correlation of 0.55 between predicted and actual changes in cognitive scores.

Conclusions:

• Intra- and inter-network functional connectivity within the default mode network are associated with cognitive changes in cognitively normal individuals over two years.
• These findings highlight the DMN's critical role in maintaining cognitive function during aging.
• Suggests potential for using DMN connectivity as a biomarker for cognitive aging.