The Development of Lateralized Brain Oscillations in Infants: Lessons From Autism.

Researchers used brain scans (EEG) to study babies at higher risk for autism during their first year of life. They found that babies later diagnosed with autism showed different brain activity patterns by 12 months, especially in areas important for hearing and language. Typical babies showed expected changes in brain patterns between 6-12 months, but babies with autism developed differently. This suggests autism-related brain differences may start appearing in the first year of life.

This longitudinal study examined brain lateralization patterns in infants at elevated likelihood for autism spectrum disorder (ASD) using EEG data from the International Infant EEG Data Integration Platform. Researchers tracked brain oscillatory activity at 6 and 12 months of age, focusing on gamma band lateralization. Key findings revealed differences in gamma band lateralization at 12 months in infants later diagnosed with ASD, but not at 6 months. Control infants showed a developmental shift from high left gamma asymmetry at 6 months toward greater symmetry by 12 months, while ASD infants showed different trajectories.

Differences were particularly notable in auditory network regions important for language learning, suggesting atypical brain development patterns may emerge during the first year of life.

Findings suggest brain lateralization differences in autism may emerge between 6-12 months, potentially informing early identification strategies. However, clinical applications require further validation. The focus on auditory network differences may guide targeted early language interventions for at-risk infants.

Sample size not reported. Study type unclear. Limited to EEG measurements which provide indirect measures of brain activity. Findings need replication in larger, independent samples. Long-term outcomes beyond 12 months not examined.

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.