SOCIAL DIFFICULTIES IN AUTISM MAY BE LINKED TO OUT-OF-SYNC VISUAL AND MOTOR NETWORKS

Written by: Dr. Christiane Rohr

Children with Autism Spectrum Disorders (ASD) often have problems learning social behaviors. This is, in part, because imitating other people's social behaviors doesn’t come as easy to them as it does to typically developing children. The ability to imitate depends on the ability to observe and to replicate facial expressions or gestures, and is subserved by brain mechanisms that link visual input (the observation) to a motor output (the replication).

A recent study conducted by a team at Johns Hopkins University in Baltimore, MD, investigated whether this link between visual input and motor output may be affected in ASD. Using functional magnetic resonance imaging (fMRI), they measured neuronal activity in visual and motor brain networks in fifty children with, and fifty children without ASD, between the ages of 8 and 12. Children were instructed to rest, which allowed the researchers to assess whether children with ASD were different from typically developing children in this regard even when they were doing nothing. In line with their assumption, they found that neuronal activity between specific visual areas and specific motor areas was more synchronized in typically developing children than it was with children with ASD. Moreover, they found that the degree to which these visual areas and motor areas were out-of-sync predicted the severity of social difficulties in the children with ASD.

In essence, the findings of this study suggest that children with ASD may have a disadvantage in imitating social behaviors due to an asynchrony in neuronal activity between visual and motor areas. This hints at the possibility that if we can find a way to re-synchronize these areas, it may allow children with ASD to more easily imitate social behaviors. However, the asynchrony in neuronal activity when the children were doing nothing in particular does not necessarily extend to when they imitate social interactions, and future studies will be needed to first test this assumption.

 

Reference: 

Nebel MB, Eloyan A, Nettles CA, Sweeney KL, Ament K, Ward RE, Choe AS, Barber AD, Pekar JJ, Mostofsky SH (2015): Intrinsic Visual-Motor Synchrony Correlates With Social Deficits in Autism. Biol Psychiatry. doi: 10.1016/j.biopsych.2015.08.029. 
http://www.ncbi.nlm.nih.gov/pubmed/26543004