Unveiling the hidden electroencephalographical rhythms during development: aperiodic and periodic activity in healthy subjects

Objective The study analyzes power spectral density (PSD) components, aperiodic (AP) and periodic (P) activity, in resting-state EEG of 240 healthy subjects from 6 to 29 years old, divided into 4 groups. Methods We calculate AP and P components using the ( Fitting Oscillations and One-Over-f (FOOOF)) plugging in EEGLAB. All PSD components were calculated from 1-45Hz. Topography analysis, Spearman correlations, and regression analysis with age were computed for all the components. Results AP and P activity show different topography across frequencies and age groups. Age-related decreases in AP exponent and offset parameters lead to reduced power, while P power decreases (1-6Hz) and increases (10-15Hz) with age. Conclusions We support the distinction between the AP and P components of the PSD and its possible functional changes with age. AP power is dominant in the configuration of the canonical EEG rhythms topography, although P contribution to topography is embedded in the canonical EEG topography. Some EEG canonical characteristics are similar to those of P component, as topographies of EEG rhythms (embedded) and increases in oscillatory frequency with age. Significance We support that spectral power parameterization improves the interpretation and neurophysiological and functional accuracy of brain processes. Highlights Differential topography for aperiodic and periodic EEG components. Power decrease in aperiodic component (exponent and offset) with age. Decrease (lower frequencies) and increase (higher frequencies) of periodic component.