Objectives: The main objective was to examine the brain activation and synchronization of MNS, CMS and ToM networks in mental state attribution in high-functioning children with autism.

Methods: Thirteen children with high-functioning autism (mean age 12.5 years) and thirteen age- and IQ- matched controls (mean age 12.9 years) participated in this study. Nine silent animations, lasting 34-45s each, were shown on a computer screen. All featured a big red triangle and a small blue triangle moving about on a framed white background. Participants were asked to watch the animation and comprehend the meaning of the actions.

Results: The participants with autism activated less relative to controls in two key networks, the Theory of Mind (ToM) network (medial frontal and superior temporal cortex), and an anterior component of the MNS (bilateral inferior frontal gyrus). The autism group activated more in areas associated with the “default network” (CMS: the anterior and posterior cingulate cortices, and the precuneus). In addition, the components of ToM network were less synchronized in participants with autism relative to controls.

Conclusions: Mental state attribution is a complex function involving simulation, self-other understanding, evaluation, and reasoning; and the components of this network function atypically in autism. It is possible that the functions mediated by the CMS, MNS and ToM structures may not be perfectly distinct. Perhaps what matters more is the functional synchrony of these structures and that is where people with autism falter.