Contrasting Connectomic Topologies and Inhibitory Chronometry in Schizophrenia and Autism Spectrum Disorder: A Multi-Modal Investigation of Stage-Specific Neurocomputational Divergence

Abstract

**Context: this is the empirical "follow-up" to the earlier theoretical synthesis regarding ASD and SSD, linked on Zenodo here: https://doi.org/10.5281/zenodo.23052633.** Background: Schizophrenia and autism spectrum disorder (ASD) share social and executive deficits in adulthood. We evaluated whether connectomics and motor chronometry provide convergent evidence for stage-specific neurodevelopmental divergence. Methods: Two multi-site cohorts were analyzed across distinct developmental windows. Study 1 evaluated resting-state fMRI in autism (ABIDE, N = 861; Craddock 200 atlas), modeling local clustering (Cglobal) with fixed-effects regression and HC3 standard errors. Study 2 examined motor inhibition, reaction time variability (RTV), and sequential risk in schizophrenia (UCLA CNP, N = 268; schizophrenia n = 50, ADHD n = 43, bipolar n = 49, controls n = 126) using Stop-Signal and BART tasks, decomposing Go response times into Ex-Gaussian parameters (μ, σ, τ). Results: In Study 1, local clustering was elevated in autism (b = 0.0096, p = .034) and showed a negative age interaction (b = -0.0012, p = .045), independent of ADOS-2 severity. In Study 2, schizophrenia selectively exhibited elevated Go RTV (b = 0.0360, FDR q = .003; BF10 = 54.36), sequential risk aversion (b = -0.1982, FDR q = .006, IRR = 0.820), and trend-level motor braking delays (SSRT: b = 54.77 ms, FDR q = .051; BF10 = 6.75). Ex-Gaussian decomposition isolated deficits to baseline slowing (μ: FDR q = .066) and candidate exponential tail expansion (τ: b = 19.84 ms, FDR q = .066; BF10 = 3.40). ADHD and bipolar comparison cohorts showed intact chronometry. Conclusions: Connectomic topology and inhibitory chronometry identify complementary computational endophenotypes across stage-specific windows, supporting the Dual-Phase divergence model. Keywords: schizophrenia; autism spectrum disorder; connectomics; executive function; stop-signal task; synaptic pruning.