Researchers from Carnegie Mellon University have come up with a simple imaging technique to detect autism.
Currently, doctors make an autism diagnosis using screening tools like the Autism Diagnostic Observation Schedule (ADOS) method, which involves a series of interviews and observations. The new method gauges a person’s verbal and physical behavior, and uses a combination of functional magnetic resonance imaging (fMRI) and machine-learning techniques to make sense of brain activation patterns and to form a diagnosis. According to the researchers, it’s 97 percent accurate.
In typically developing people, certain thoughts and emotions show similar neural signatures, or patterns of activity in the brain. That means brain disorders might also show differences in thought activation patterns.
Thought-Markers in Autism Patients Are Unique
The researchers, who published their report in PLOS ONE, say they can see changes in the way certain concepts are represented in the brains of people with autism. They call these alterations “thought-markers.”
“We found that we could tell whether a person has autism or not by their brain activation patterns when they think about social concepts. This gives us a whole new perspective to understanding psychiatric illnesses and disorders,” said Marcel Just, the D.O. Hebb University Professor of Psychology in the Dietrich College of Humanities and Social Sciences at Carnegie Mellon.
“We've shown not just that the brains of people with autism may be different, or that their activation is different, but that the way social thoughts are formed is different,” he said. “We have discovered a biological thought-marker for autism.”
Just scanned the brains of 17 people with high-functioning autism, along with those of 17 control people. Volunteers were asked to think about 16 social concepts or interactions, such as hugging, persuading, and adoring.
The control patients showed brain activation indicating a representation of the self in the posterior midline region of the brain — something almost completely absent in the patients with autism.
“When asked to think about persuading, hugging, or adoring, the neurotypical participants put themselves into the thoughts; they were part of the interaction. For those with autism, the thought was more like considering a dictionary definition or watching a play — without self-involvement,” Just said.
Method Could Be Used to Make Other Diagnoses
Just has already begun to further his research, and says it could extend to other psychiatric illnesses, such as obsessive-compulsive disorder. The concepts used in this research involved social interaction, which is altered in autism. To detect a different disorder, such as paranoia, he said he might use concepts related to persecution, or being watched or followed.
Just wants to compare the new method to ADOS and involve more participants to pinpoint any major differences in the two techniques. His next study will involve 100 volunteers in each study group.
"This is a potentially extremely valuable method that could not only complement current psychiatric assessment,” Just said. “It could identify psychiatric disorders not just by their symptoms but by the brain systems that are not functioning properly.”