Altered spectral patterns of aperiodic electroencephalography in autism

Area of Science:

• Neuroscience
• Developmental Psychology
• Biomedical Engineering

Background:

• Altered neural excitation/inhibition (E/I) ratio is implicated in autism spectrum disorder (ASD) etiology.
• Previous research suggests lower E/I ratios in specific brain regions of autistic individuals.
• The presence of E/I imbalance in autistic adolescents and adults and its correlation with clinical manifestations remain unclear.

Purpose of the Study:

• To investigate the E/I ratio in autistic adolescents and adults.
• To examine the relationship between E/I imbalance and clinical features of ASD.
• To utilize resting-state electroencephalography (EEG) signals for E/I ratio assessment.

Main Methods:

• Recruited 63 autistic adolescents/adults and 53 non-autistic comparisons (NAC).
• Recorded resting-state EEG for 3 minutes with eyes closed.
• Applied fitting oscillations and one-over-F function to analyze periodic and aperiodic spectral components.

Main Results:

• Autistic participants showed a flatter spectrum power slope and smaller offset compared to NAC.
• Higher Autism Spectrum Quotient (AQ) scores correlated with lower aperiodic exponent in ASD.
• In ASD, lower aperiodic exponent was linked to difficulties in mindreading, registration, and working memory.

Conclusions:

• Flatter aperiodic component slopes in frontal and posterior regions of ASD participants support an E/I imbalance.
• The spectral slope may correlate with autistic severity, empathy, sensory characteristics, and working memory.
• Further investigation is warranted to explore these associations.