Discovery of Neurocognitive Phenotypes of Autism By Analyzing Functional Connectivity in the Default Mode Network and Dorsolateral Prefrontal Cortex

Autism spectrum disorder (ASD) is a neurodevelopmental disorder usually presenting as reduced social interaction, lessened verbal communication, and repetitive behavior. Diagnosing autism spectrum disorder is extremely difficult because of its wide variety of symptoms, so it can only be diagnosed through behavioral tests and analysis of developmental history. Resting-state functional magnetic resonance imaging (rs-fMRI) can help researchers discover a neural substrate for autism spectrum disorder to diagnose it earlier. One prominent fMRI database for autism spectrum disorder research is the Autism Brain Imaging Data Exchange, a large-scale collection of anonymized functional MRI scans subdivided by age, gender, handedness, and scores on behavioral assessments.  This analysis focused on two brain networks: the default mode network (DMN), which is active when minds wander, and the executive network, which is active during the performance of tasks. The medial prefrontal cortex (mPFC), posterior cingulate cortex (PCC), and angular gyrus are nodes of the default mode network, and the dorsolateral prefrontal cortex (DLPFC) is the main node in the executive network. Both networks are affected by autism spectrum disorder. This research used preprocessed resting-state fMRI data to establish neurocognitive phenotypes for autism spectrum disorder. Bivariate correlation was used to compare connectivity in the default mode network and dorsolateral prefrontal cortex between autism spectrum disorder fMRI scans and control fMRI scans, and these differences were analyzed for correlations with each patient’s assessment scores. After the Benjamini-Hochberg procedure was applied to reduce the false discovery rate, analysis of these metrics revealed that in autism spectrum disorder patients there was underconnectivity between the right posterior cingulate cortex and the right medial prefrontal cortex, while in control patients there was overconnectivity between the right angular gyrus and left dorsolateral prefrontal cortex. Autism spectrum disorder is extremely heritable, so phenotypic research is absolutely necessary for discovering more about the genetic causes of autism spectrum disorder, which will speed up autism spectrum disorder diagnosis and help researchers develop more targeted treatments for autism spectrum disorder.