Electrophysiological signatures of brain aging in autism spectrum disorder.

Emerging evidence suggests that aging processes may be altered in adults with autism spectrum disorder (ASD). However, it remains unclear if oscillatory slowing, a key neurophysiological change in the aging brain, manifests atypically in this population. This study sought to examine patterns of age-related oscillatory slowing in adults with ASD, captured by reductions in the brains peak alpha frequency. Resting-state EEG data from adults (18-70 years) with ASD (N=93) and age-matched neurotypical (NT) controls (N=87) were pooled from three independent datasets. A robust curve-fitting procedure quantified the peak frequency of alpha oscillations (7-13Hz) across all brain regions. Associations between peak alpha frequency and age were assessed and compared between groups. Consistent with characteristic patterns of oscillatory slowing, peak alpha frequency was negatively associated with age across the entire sample (p<.0001). A significant group by age interaction revealed that this relationship was more pronounced in adults with ASD (p<.01), suggesting that that age-related oscillatory slowing may be accelerated in this population. Scalable EEG measures such as peak alpha frequency could provide insights into neural aging that are crucially needed to inform care plans and preventive interventions that can promote successful aging in ASD.