Abstract
The lateralization of brain activity is important for language processing and attention, and atypical patterns of lateralization have been linked to many neurodevelopmental disorders, including autism spectrum disorder (ASD). However, the developmental timing of these patterns and their relationship to emerging ASD characteristics are unclear. In this study, we used data from EEG-IP (International Infant EEG Data Integration Platform), a longitudinal cohort bringing together infants at elevated likelihood for ASD and age-equivalent controls across two sites. We examined brain lateralization in electroencephalography (EEG) power during the first year of life. Overall, we identified differences in gamma band lateralization in infants later diagnosed with ASD at 12 months but not at 6 months. Additionally, we observed a shift from high left gamma band asymmetry at 6 months toward more symmetry by 12 months in our control group, highlighting between-group differences in developmental trajectories in brain oscillatory activity. We found key differences in the lateralization across groups in brain regions within the auditory network, which is thought to be important for language learning. Overall, examining the developmental trajectories of lateralization is a crucial step toward creating more accurate models of brain development and better understanding the underlying mechanisms of neurodevelopmental disorders.