Individualized brain networks and language lateralization emerge in toddlers before age five

Toddlers' brains show individualized functional networks and emerging language lateralization before age five. Researchers developed an age-appropriate reference capturing common structure and individual variability in children aged 8-60 months. This allowed estimation of each child's brain networks from fMRI scans. These findings suggest behaviorally relevant brain networks emerge much earlier than previously thought, offering a foundation for studying development and early biomarkers.