An Exploratory Age-Adjusted Model of Individual Alpha Peak Frequency in Healthy Older Adults: A FOOOF-Based Spectral...

Individual alpha peak frequency (iAPF) is a stable neurophysiological marker associated with cognitive processing and healthy brain aging. However, the interpretation of alpha activity in older adults remains limited by the use of fixed canonical frequency bands, which may not adequately capture age-related slowing. The aim of this study was to develop an exploratory age-adjusted model of iAPF in cognitively healthy older adults using FOOOF-based spectral parameterization of resting-state EEG. Eighty-one participants aged 52-87 years were selected from the PDWAVES database. Resting-state, eyes-closed EEG recordings were analyzed over nine parieto-occipital electrodes, and iAPF was defined as the center frequency of the highest alpha peak within the 7-14 Hz range after separating periodic and aperiodic spectral components. Linear regression showed a significant negative association between age and iAPF, described by the equation iAPF = 13.22 - 0.054 × age (F(1,79) = 19.56, p < 0.001), indicating an average decrease of 0.54 Hz per decade. Age explained 19.8% of the variance (R² = 0.198), with a mean iAPF of 9.527 ± 1.064 Hz. Bootstrap resampling confirmed that the age-iAPF association was statistically reliable (95% CI for the slope excluding zero), although cross-validation indicated limited predictive performance on held-out data (10-fold mean R² = 0.019; LOOCV R² = 0.155). These findings provide a preliminary age-adjusted reference equation for describing iAPF trajectories in healthy older adults at the group level and support the use of spectral parameterization as a more specific alternative to fixed-band approaches in aging research.