Redundancy protects processing speed in healthy individuals with accelerated brain aging

Area of Science:

• Neuroscience
• Computational Neuroscience
• Cognitive Neuroscience

Background:

• Brain age (BA) estimation from neuroimaging offers a potential biomarker for brain health.
• The brain-age gap (BA gap) shows weak correlations with cognition in healthy aging, suggesting compensatory mechanisms.
• Investigating neuroprotective factors against accelerated brain aging is crucial for understanding cognitive decline.

Purpose of the Study:

• To investigate the neuroprotective role of brain network redundancy against accelerated brain aging.
• To examine the association between brain age gap, cognitive function, and brain network topology.
• To identify specific network features that may mitigate cognitive impacts of accelerated brain aging.

Main Methods:

• Deep learning was used to estimate brain age from structural MRI.
• Diffusion MRI and tractography were employed to derive network topology.
• Associations between chronological age, brain age, BA gap, cognitive measures, and network topology were analyzed.

Main Results:

• Chronological age and brain age were similarly related to cognition and network topology; BA gap showed weaker relationships.
• Individuals with accelerated brain aging (BA gap+) exhibited reduced average degree and redundancy in the dorsal attention network.
• Redundancy within the dorsal attention network positively correlated with processing speed in individuals with accelerated brain aging.

Conclusions:

• Brain network redundancy, particularly in the dorsal attention network, may play a neuroprotective role.
• This redundancy might mitigate the negative effects of accelerated brain atrophy on cognitive performance.
• Findings highlight the importance of network topology in understanding cognitive aging and brain health.