Wired Differently? Brain Temporal Complexity and Intelligence in Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) is characterised by atypical behavioural and cognitive diversity, yet the neural underpinnings linking brain activity and individual presentations remain poorly understood. In this study, we investigated the relationship between resting-state functional magnetic resonance imaging (fMRI) signal complexity and intelligence (full-scale intelligence quotient (FIQ); verbal intelligence quotient (VIQ); and performance intelligence quotient (PIQ); in male adults with ASD (n = 14) and matched neurotypical controls (n = 15), using three complexity-based metrics: Hurst Exponent (H), fuzzy approximate entropy (fApEn), and fuzzy sample entropy (fSampEn). Using a whole-brain measure, ASD participants showed significant negative correlations between PIQ and both fApEn and fSampEn, suggesting that increased neural irregularity may relate to reduced cognitive-perceptual performance in autistic individuals. No significant group association with complexity were found in the control group. These findings provide insight into how cognitive functions in autism may not only reflect deficits but also an alternative neural strategy, suggesting that distinct temporal patterns may influence intelligence in ASD. These preliminary findings could inform clinical practice and influence health and social care policies, particularly in autism diagnosis and personalised support planning.