Preserved intrinsic neural timescale organization with hierarchical variation in autism spectrum disorder

Intrinsic neural timescales (INTs) index the temporal decay of neural activity and form a hierarchy from fast sensorimotor to slow transmodal regions. Although altered INTs have been reported in autism spectrum disorder (ASD), it remains unclear whether this hierarchical organization is preserved and how individual variability along it relates to sensory traits. Using resting-state fMRI from 182 participants (67 ASD, 115 typically developed controls [TDC]), we estimated INTs from the autocorrelation half-life and averaged them across four runs. The cortical INT hierarchy was preserved in ASD, with comparable sensorimotor-to-transmodal organization across groups. Regions operating at longer timescales exhibited relative prolongation in ASD, with effect size increasing along the hierarchy. However, no statistically significant group differences were identified at any spatial resolution examined. To characterize individual INT profiles relative to a TDC-derived template, we decomposed each participant's profile into global shift, hierarchical scaling, and residual deviation components. Global shifts and hierarchical scaling were associated with demographic variation (primarily sex) rather than diagnosis, whereas residual deviations showed a modest association with sensory traits characterized by reduced sensory registration. These findings indicate that large-scale temporal organization is largely preserved in ASD, while individual-specific deviations from this hierarchy may underlie variability in sensory experience.