Age-related differences in resting-state, task-related, and structural brain connectivity: graph theoretical analyses
David J Madden1,2,3, Jenna L Merenstein4, Hollie A Mullin4,5
1Brain Imaging and Analysis Center, Duke University Medical Center, Box 3918, Durham, NC, 27710, USA. david.madden@duke.edu.
Brain Structure & Function
|June 10, 2024
Summary
Aging brains show reduced system segregation, especially during tasks. This age-related increase in brain module integration impacts visual search performance differently based on functional versus structural connectivity.
Area of Science:
- Neuroscience
- Cognitive Aging
- Brain Connectivity
Background:
- Aging is linked to decreased functional brain connectivity and module segregation.
- Task performance, compared to resting state, shows more pronounced age-related decreases in module segregation.
Purpose of the Study:
- Investigate age-related differences in whole-brain system segregation using graph-theoretical analysis.
- Examine how functional and structural connectivity changes with age affect visual search performance.
Main Methods:
- Collected resting-state, task-related (visual search), and structural MRI data from 68 healthy adults (18-78 years).
- Utilized graph-theoretical analyses and module parcellation from resting-state fMRI data.
- Assessed system segregation and reconfiguration from rest to task.
Main Results:
- The decrease in system segregation from rest to task (reconfiguration) increased with age.
- Structural system segregation increased with age, indicating weaker within- and between-module connectivity.
- Functional and structural system segregation differentially impacted age-related visual search decline: functional affected evidence accumulation, while structural affected encoding and response times.
Conclusions:
- Age-related increases in brain module integration (reconfiguration) are necessary for attentional demands during tasks like visual search.
- Both functional and structural brain connectivity changes contribute to age-related cognitive decline, but through distinct mechanisms.
- Functional and structural system segregation's age-related differences are largely independent.
