Researchers have found extra-dense connections within certain brain networks in children with autism spectrum disorder (ASD).
This hyperconnectivity supports the idea that autism-related talents, as well as disabilities, may stem from differences in brain “wiring,” the researchers say. The findings also add to a growing body of research aimed at identifying biomarkers that could enable earlier and clearer diagnosis of autism.
“This study will advance our quest for reliable, biologically based markers of autism,” comments Daniel Smith, Ph.D., Autism Speaks senior director for discovery neuroscience. “The findings may offer a glimpse into the future of autism medicine, when diagnosis and treatments will come from our understanding of the brain and body processes that go awry in autism, rather than subjective ratings of behavior.”
The investigators, from Stanford University, used MRI scans to look at the density of connections within several brain networks. Study participants included 40 children, ages 7 to 12. Twenty had autism. However, the need for cooperation during the MRI procedure required that they be verbal and on the less severely disabled end of the autism spectrum. For comparison, the researchers included 20 age-matched children without ASD.
The team found "hyperconnectivity" within five large brain networks. The dense interconnections were highest in the so-called “salience network.” Prior research has suggested that this network integrates incoming sensory information with internal emotions. In doing so, it helps direct attention to “salient,” or important, information in a person's environment. In particular, it appears to be crucial for responding appropriately to social cues.
Hyperconnectivity corresponds with symptoms
In addition, the investigators found that the denser the interconnections within a child’s salience network, the more severe his or her repetitive behaviors or restricted interests. This hyperconnectivity might also underlie certain positive autism traits such as exceptional focus and skill in a particular area, they propose.
Biomarkers to guide diagnosis and treatment
By looking at the children’s MRI brain patterns, the researchers found they could accurately determine which had autism and which did not 78 percent of the time. As such, the findings add to a small but growing number of brain-imaging studies that identify biological signs of autism. (Also see “Discovery of Pre-symptom Marker of Autism.”)
More research is needed to see if such patterns can be seen in younger children – before outward autism symptoms appear. In addition, further study is needed to see if the findings apply to nonverbal and severely disabled individuals with autism.
Autism Speaks is currently funding a broad range of studies on the brain biology of autism and how it can guide diagnosis and treatment. You can explore these and other funded research using this website’s Grant Search.
For more insights into the autism brain, also see these recent news stories:
* Study Links Autism to Impaired Brain Relay Station
* In Autism, Voices May Fail to Engage Brain Reward Center
* Brain Responses to Words Predict Development in Toddlers with Autism