New non-verbal marker could help diagnose autism
There may be a new way to help screen for autism that uses neural markers. Researchers from Dartmouth led a study that identified the first neural, non-verbal marker of autism of its kind.
Currently, screening for Autism Spectrum Disorder (ASD) is difficult because there is no conclusive test to prove a diagnosis as there are for other diseases. Doctors screen for specific behavior and development delays.
Even if a trained clinician suspects ASD, an official diagnosis may not come until much later.
In this study, researchers were able to identify an objective, non-verbal marker of autism independent of intelligence.
“Autism is hard to screen for in children, when the first signs are present. A trained clinician may be able to detect autism at 18-months or even younger; yet, the average age of a diagnosis of autism in the U.S. is about four years old,” said Caroline Robertson, the lead author of the study. “We need objective, non-invasive screening tools that don’t depend on assessing a child’s behavior.”
It’s been thought that people with autism have differences in the way neural signals are inhibited in the brain and how certain information is processed.
Robertson’s past research found that when presented two images at the same time, an autistic brain is slower when switching back and forth from one image to the other, something called slower binocular rivalry.
In this new study, the researchers measured the rate of slower binocular rivalry in people with autism using an electroencephalography (EEG) electrode placed over the visual region of the brain on a participants head.
Once the electrode was in place, participants were shown two images that flickered back and forth.
The EEG neural data were then used to predict whether or not an individual had autism, and the researchers were able to accurately identify autism in the brain 87 percent of the time.
The study paves the way for developing new non-verbal markers for diagnosing and screening for ASD.
“This visual test may be a non-verbal marker of autism in adults,” said Robertson, “Our next steps are to learn whether this test could potentially be used to detect autism in pre-verbal children and non-verbal adults and develop it into a screening tool for the condition. In the meantime, this result gives us new insight into the brain in autism, showing that visual regions of the brain are affected.”
The study findings were published in the journal Current Biology.
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