Alterations of Functional Connectivity in Autism and ADHD Revealed by Multi-Voxel Pattern Analysis.

Background Autism and Attention Deficit Hyperactivity Disorder (ADHD) are comorbid neurodevelopmental disorders that share common and distinct neurobiological mechanisms, with disrupted brain connectivity patterns being a hallmark feature of both conditions. It is challenging to gain a mechanistic understanding of the underlying disorder because brain connectivity changes in autism and ADHD are heterogeneous. Objectives The present resting state functional MRI (rs-fMRI) study focuses on investigating the shared and distinct rs-fMRI connectivity (rsFC) patterns in autistic and ADHD adults using Multivoxel Pattern Analysis (MVPA). By identifying spatial patterns of fMRI activity across a given time course, MVPA is an innovative and powerful method for generating seed regions of interest (ROIs) without a priori hypotheses. Methods We performed a data-driven, whole-brain, connectome-wide MVPA on rs-fMRI data collected from 15 autistic, 19 ADHD, and 15 neurotypical (NT) young adults. Results MVPA identified cerebellar vermis 9, precuneus, and the right cerebellum VI for autistic vs NT, right inferior frontal gyrus and vermis 9 for ADHD vs NT, and right dorsolateral prefrontal cortex for autistic vs ADHD as significant clusters. Posthoc seed-to-voxel analyses using these clusters as seed ROIs were performed for further characterization of group differences. The cerebellum VI, vermis, and precuneus in autistic adults, and the vermis and frontal regions in ADHD showed different connectivity patterns in comparison with NT. Conclusions The study characterizes the rsFC profile of cerebellum with key cortical areas in autism and ADHD, and emphasizes the importance of studying the role functional connectivity of cerebellum in neurodevelopmental disorders.