Brain scan complexity peaks near age 23 in healthy people
An observational analysis of 504 healthy people aged 6 to 85 estimated a peak at age 23 and linked complexity to cognitive performance.
Limit: Very young and very old participants were underrepresented
Edited by Boris Djordjevic · AgingResearch.News
In a cross-sectional observational study, researchers analyzed resting brain scans from 504 healthy people aged 6 to 85. Each scan lasted 10 minutes. They measured the complexity of signal patterns across different timescales, then fitted curves relating that measure to age. The estimated overall peak occurred at age 23, with lower complexity at older ages.
Among 494 participants with sufficiently complete cognitive test data, greater complexity in certain brain regions was linked to faster performance on tests requiring mental flexibility or control over automatic responses. The regions associated with performance differed between tests.
Why it matters
The authors suggest that brain-scan complexity may offer a noninvasive indicator of information-processing capacity, potentially helping researchers understand how brain function varies across life.
Caveats
This cross-sectional study compared different people rather than following individuals as they aged, and very young and very old participants were underrepresented. The main cognitive analyses did not adjust for age, although some associations remained in an age-adjusted analysis.
- Color Word Interference Test Inhibition and Inhibition/Switching
- fMRI complexity
- Multiscale Sample Entropy
- Trail Making Test number-letter switching
- Humans
The paper
University of Southern California
NeuroImage, Jul 1, 2026, Open access
