Lifespan EEG reference charts disentangle alpha-band alterations in neurological and neuropsychiatric disorders

The study created brain reference charts for alpha frequency and power based on EEG recordings from 22,094 patients aged 1 to 100 years. Researchers found that alpha power was consistently reduced in patients with mental disorders compared to age-matched norms. However, analysis of alpha frequency showed a method-dependent difference: standard analysis suggested alpha slowing, while after adjusting for aperiodic components, alpha rhythm actually accelerated. These findings demonstrate that aperiodic components in EEG spectra can mask true changes in oscillatory activity. The research suggests that the frequently reported alpha slowing in mental disorders may partly reflect changes in aperiodic neural activity rather than true deceleration of alpha oscillations.