Altered spectral patterns of aperiodic electroencephalography in autism.

Researchers studied brain wave patterns in 63 autistic teens and adults compared to 53 non-autistic people. They found that autistic participants had different electrical brain activity patterns, suggesting an imbalance between brain signals that excite versus calm neural activity. This imbalance was linked to greater autism traits and difficulties with understanding others' thoughts, sensory processing, and memory tasks.

This study investigated neural excitation-inhibition (E/I) balance in 63 autistic adolescents and adults compared to 53 non-autistic controls using resting-state EEG. Researchers analyzed aperiodic brain activity patterns by separating periodic and aperiodic components of EEG signals. Autistic participants showed flatter spectral power slopes and smaller offsets compared to controls, suggesting altered E/I balance. Higher Autism Spectrum Quotient scores correlated with lower aperiodic exponents in the autism group.

Lower aperiodic exponents were associated with greater difficulties in mindreading, sensory registration, and working memory. The flatter slopes across frontal and posterior brain regions support the hypothesis of E/I imbalance in autism spectrum disorder.

EEG aperiodic patterns may serve as potential biomarkers for E/I imbalance in autism. Findings could inform targeted interventions addressing sensory processing, social cognition, and working memory challenges. Further research needed to establish clinical utility and treatment implications.

Single study with moderate sample size. Cross-sectional design limits causal inferences. EEG methodology may not capture all aspects of E/I balance. Unclear generalizability across different autism presentations and age ranges.

The altered ratio of neural excitation (E) and inhibition (I) has been proposed to the etiology of autism spectrum disorder (ASD). Previous studies suggested a lower E/I ratio in autistic individuals compared to non-autistic comparisons (NACs) in specific brain regions. Whether the E/I imbalance was present in ASD in adolescence and adulthood and how the ratio correlated with clinical manifestations are unclear. This study aimed to investigate the E/I ratio in autistic adolescents and adults by using resting-state electroencephalography (EEG) signals.

The study recruited 63 autistic adolescents and adults, and 53 NAC. EEG was recorded while participants were asked to stare at the cross mark on the monitor and close their eyes for 3 min each. We used fitting oscillations and one-over-F function to separate periodic and aperiodic components, then fitting the curve to a linear line. Autistic participants exhibited a flatter spectrum power slope and a smaller offset compared to NAC.

Group differences existed in the relationship between slope and Autism Spectrum Quotient (AQ) scores, with higher AQ total scores correlated with lower aperiodic exponent in ASD. In ASD, a lower aperiodic exponent was significantly correlated with greater difficulty in mindreading, low registration, and working memory difficulty. The slope of the aperiodic component in ASD was flatter across frontal and posterior regions, supporting that the ASD group may have an E/I imbalance. Besides, the slope might be associated with overall autistic severity, empathy, sensory characteristics, and real-world working memory difficulties that warrants further investigation.