Age-specific pediatric templates improve EEG source-reconstructed biomarkers in children

EEG source reconstruction requires an anatomical head model, ideally constructed from individual magnetic resonance imaging (MRI) scans. In developmental studies of children and adolescents, however, MRIs are rarely available. Researchers therefore routinely rely on adult templates, such as the FreeSurfer average (fsaverage), despite substantial anatomical changes throughout development. How much this reliance on adult models biases downstream EEG biomarkers remains unclear. Here, we investigated whether age-specific pediatric templates offer a better alternative to fsaverage for EEG-derived biomarkers in children and adolescents, using individual MRI-based reconstruction as the reference. We analyzed eyes-closed resting-state EEGs from 384 Healthy Brain Network participants aged 5.5 to 17.5 years. For each participant, we tested three anatomical models: their individual MRI, an age-specific pediatric template from a series spanning ages 6-17 at one-year intervals, and the adult fsaverage template. We compared four EEG biomarkers in childhood and adolescence: absolute power, relative power, long-range temporal correlations quantified with detrended fluctuation analysis (DFA), and functional excitation-inhibition (fE/I) ratio. Pediatric templates agreed more closely with individual MRI-based biomarkers in both developmental groups and had fewer parcels with significantly different biomarker values than the adult template, except for absolute power in older adolescents. We conclude that when individual MRI is not available, age-specific pediatric templates match individual MRI-based EEG biomarker values more closely than the adult template across all four biomarkers up to approximately 12 years of age and should be the preferred choice at least up to this age.