April 17, 2014
Atypical Brain Connectivity Associated With Autism Spectrum Disorder
Autism spectrum disorder (ASD) in adolescents appears to be associated with atypical connectivity in the brain involving the systems that help people infer what others are thinking and understand the meaning of others' actions and emotions.
The ability to navigate and thrive in complex social systems is commonly impaired in ASD, a neurodevelopmental disorder affecting as many as 1 in 88 children.The authors used functional magnetic resonance imaging to investigate connectivity in two brain networks involved in social processing: theory of mind (ToM, otherwise known as the mentalizing system, which allows an individual to infer what others are thinking, their beliefs, their intentions) and the mirror neuron system (MNS, which allows people to understand the meanings and actions of others by simulating and replicating them). The study included 25 adolescents with ASD (between the ages of 11 and 18) and 25 typically developing adolescents.
Compared to typically developing adolescents, those with ASD showed both over- and under-connectivity in the ToM network, which was associated with greater social impairment. The adolescents with ASD also had increased connectivity between the regions of the MNS and ToM, suggesting that ToM-MNS "cross talk" might be associated with social impairment.
"This excess ToM-MNS connectivity may reflect immature or aberrant developmental processes in two brain networks involved in understanding of others, a domain impairment in ASD. Further, robust links with sociocommunicative symptoms of ASD implicate atypically increased ToM-MNS connectivity in social deficits observed in ASD."
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