Cerebral CortexNov 2, 2026, 06:14 GMT

Brain-wave measures stayed reliable over five years in adults

In adults tested about five years apart, four brain-wave measures had reliability scores of 0.51 to 0.88, rated fair to excellent.

Paper by Polina Politanskaia, Jacinta Bywater, Anna J Finley, +4Douglas Jozef Angus · Bond University

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Biomarkers

Studied:: Cohort study of 208 returning adults, about five years
What changed:: Brain-wave measures had fair to excellent reliability scores of 0.51 to 0.88 over about five years
The catch:: Only 208 of 608 returned, and returnees were older than nonreturnees
Why it’s aging research:: It looks at how biology varies with age or lifespan.

Editor of record: Boris Djordjevic · AgingResearch.News

Paper

An observational study measured resting brain activity in 608 adults aged 20–70 from Dortmund, Germany, and retested 208 about five years later. The returning group included 130 women and 78 men. Researchers used electroencephalography, which records the brain’s electrical activity through scalp sensors. Each session included three minutes with eyes closed and three with eyes open.

The four measures showed fair to excellent reliability: differences between people were broadly maintained over time. This did not mean measurements stayed unchanged. The peak frequency, or speed, of alpha brain rhythms decreased in recordings toward the back of the head. The slope describing how background signal strength falls at higher frequencies became flatter. Alpha rhythm strength remained unchanged. The researchers found no evidence that changes over time varied with participants’ starting age.

Why it matters

Tracking brain activity across adulthood requires measures that remain dependable over years. The authors called for research on whether deviations from these patterns may indicate disease.

Caveats

Only 208 of 608 participants returned, and returnees were older than nonreturnees; further data-quality exclusions varied by analysis. The sample excluded people with severe neurological diseases and psychiatric disorders, among other conditions.