Researchers have found that patterns of functional brain connectivity––the strength of connections between parts of the brain––that are unique to autism spectrum disorder (ASD) differ across the lifespan. This finding suggests that the brain characteristics underlying ASD change over time.

Appearing online March 6th in the journal NeuroImage: Clinical, the study was conducted by 2014 NARSAD Young Investigator grantee Lucina Q. Uddin, Ph.D., of the University of Miami, along with Jason S. Nomi, Ph.D. Funded in part by Dr. Uddin’s Young Investigator grant, their work examined brain connectivity at three life stages in people with and without ASD: children age 11 and younger, adolescents between the ages of 11 and 18, and adults over age 18. Breaking down the groups by age helped tease out differences across the lifespan that are often masked in studies that look at children, adolescents, or adults with ASD in a single group.

The researchers used imaging techniques to identify connections in the brain that appeared while people were resting, reflecting brain networks that are not tied to a particular activity. They tested connections both within networks responsible for certain cognitive functions, and between networks that have different cognitive functions.

Looking at these networks, Drs. Uddin and Nomi found that children with ASD had more connections within certain networks, and fewer connections between certain networks, than children without ASD. However, adolescents with ASD, showed fewer connections between networks and no difference in their connections within networks. No differences in network connectivity were found between adults with and without ASD.

These findings suggest that childhood ASD may involve unusually high levels of connectivity within specific brain areas that normalize during adolescence, and low connectivity between brain areas that normalize by adulthood. It is possible that such patterns could help detect ASD, as different patterns may signal the condition at different ages.

The brain areas examined in this study help people switch between working with stored knowledge and working with information from the environment. Faulty connections in these areas may contribute to the limited and repetitive patterns of behavior linked with ASD. More research is needed to determine how changing connectivity patterns may drive these behaviors across the lifespan, in addition to how those patterns actually change over time.

Read the abstract.