A study of sleeping toddlers identified patterns of abnormal neural activity that could aid in the early
diagnosis of autism and help to understand underlying causes. Using functional magnetic resonance
imaging (fMRI), researchers found that 72 percent of children with ASD showed decreased
synchronization across brain hemispheres in areas commonly associated with language and
communication. This decreased synchronization was rarely seen in typically developing children, or
those with delayed language development who did not have autism. Strong synchronization between
the right and left hemisphere of the brain is critical for proper functioning, and there is evidence of
disrupted synchronization in neurological disorders such as schizophrenia and Alzheimer’s disease.
While disrupted synchronization has been documented in adults with autism, researchers had been
unable to study the phenomenon in early childhood because toddlers cannot remain still long enough to
undergo a brain scan when awake. Researchers were able to overcome this challenge by performing
scans on sleeping children; neurons remain synchronized between regions of the brain with similar
function even while resting. The brain scans revealed that weak neural synchronicity is evident in the
early stages of autism and that the strength of synchronization is linked to the degree of the child’s
symptoms -- children with the weakest neural synchronization exhibit the most severe impairments. The
researchers note that measures of neural synchronization could one day play a role in early autism
diagnosis, particularly because the measure can be taken while the child sleeps.
--IACC 2011 Summary of Advances in ASD Research
