Grant: Project Grant

Autism spectrum disorder (ASD) is a common diagnosis, affecting more than 1 in 70 Canadians. While still poorly understood, mounting research suggests an association to atypical brain networks. This project will test whether ASD is associated to atypical brain network 'hierarchy', specifically a microstructural and functional imbalance between sensory/motor regions that interact with the outside world and "transmodal" association areas that are implicated in more abstract, higher cognition. To investigate network hierarchy, we will acquire magnetic resonance imaging (MRI) data in individuals with ASD as well as neurotypical controls. A precision imaging approach that involves repeated MRI scanning per participant at ultrahigh fields (i.e., 7 Tesla) will be used to maximize resolution and signal, and to reliably map cortical microstructure and function. Using analytics developed in the PIs lab, we will resolve differences in cortical microstructure between sensory/motor regions (which are myelin-rich and have marked cortical layering) from transmodal systems (which have little myelination and less demarcated layering) in both groups. Moreover, we will study how sensory/motor regions and transmodal systems functionally communicate, by modelling how signals flow from one system to the other. Statistical analyses will compare microstructural and functional properties between ASD and controls, and we will correlate findings with polygenic risk scores and behavioural measures related to autism symptoms. This project will shape our understanding of the still elusive substrate of autism, and may disentangle the relation between genetic risk, brain networks, and symptoms. Ultimately, our findings will help to develop diagnostic markers that can guide and monitor new treatments.