High-order alpha-band network reorganization underpins clinical symptom alleviation following EEG neurofeedback in preschool children with autism spectrum disorder: a multidimensional study.

Background: Autism Spectrum Disorder (ASD) is increasingly recognized as a disorder of neural connectivity and network architecture. While EEG neurofeedback (NFB) has shown clinical efficacy in ameliorating ASD symptoms, the underlying neurophysiological mechanisms-specifically regarding high-order network reorganization beyond simple power spectrum changes-remain poorly understood. Furthermore, there is a need to validate whether robust biomarkers can be identified using low-density EEG systems suitable for preschool children. Methods: In this randomized, sham-controlled trial, 40 preschool children with ASD (mean age 5.56 years) were assigned to either an active NFB group ( Results: The NFB group exhibited significant reductions in ABC total scores and Social Relating subscale scores. Neurophysiologically, while conventional Low-Order Functional Connectivity (LOFC) failed to capture significant global changes, the alpha-band HOFC revealed a systemic optimization toward a more efficient small-world architecture, characterized by increased Clustering Coefficient (CC) and Local Efficiency (LE), and decreased Characteristic Path Length (CPL). Additionally, NSE analysis indicated increased dynamic flexibility across multiple frequency bands, reflecting a reduction in neural rigidity. Crucially, the optimization of alpha-band HOFC metrics was significantly correlated with the degree of clinical symptom alleviation ( Conclusion: These findings demonstrate that alpha-band NFB facilitates clinical recovery in preschool children with ASD by inducing frequency-specific high-order network reorganization. The study suggests that alpha-band HOFC may serve as a potential exploratory electrophysiological correlate for monitoring therapeutic responses.