Scientists have developed a brain-imaging technique that may be able to detect autism spectrum disorder in only two minutes, according to new research published in the journal Clinical Psychological Science.
The scanning procedure, which reveals the brain’s response to thoughts of ‘self-perspective,’ offers promising diagnostic potential once more research is done.
In previous research using functional magnetic resonance imaging (MRI), scientists found that when it comes to recognizing “your turn” in sports or in a game, people with autism spectrum disorders show a subdued response in the brain. In fact, the more subdued the brain’s response to self-perspective, the more severe the autism symptoms.
Because of this, the researchers hypothesized that a clear biomarker for self-perspective exists and that they could evaluate it through functional MRI. They also believed that the biomarker could be used as a tool in the clinical diagnosis of people with autism spectrum disorder.
“Our brains have a perspective-tracking response that monitors, for example, whether it’s your turn or my turn,” said study author Professor Read Montague at the Virginia Tech Carilion Research Institute.
“This response is removed from our emotional input, so it makes a great quantitative marker,” he said. “We can use it to measure differences between people with and without autism spectrum disorder.”
The path to this discovery has been a long one. In a 2006 study by Montague and team, pairs of subjects had their brains scanned through MRI as they played a game requiring them to take turns. Researchers found that the middle cingulate cortex became more active when it was the subject’s turn.
“A response in that part of the brain is not an emotional response, and we found that intriguing,” said Montague, who also directs the Computational Psychiatry Unit at the Virginia Tech Carilion Research Institute and is a professor of physics at Virginia Tech.
“We realized the middle cingulate cortex is responsible for distinguishing between self and others, and that’s how it was able to keep track of whose turn it was.”
In a subsequent study, the researchers asked athletes to watch a brief clip of a physical action, such as kicking a ball or dancing, while undergoing functional MRI. The athletes were then asked either to replay the clips in their mind, like watching a movie, or to imagine themselves as participants in the clips.
“The athletes had the same responses as the game participants from our earlier study,” Montague said. “The middle cingulate cortex was active when they imagined themselves dancing — in other words, when they needed to recognize themselves in the action.”
In this case, the researchers also found that in participants with autism spectrum disorder, the more subdued the response, the more severe the symptoms.
In the current study, children were shown 15 images of themselves and 15 images of a child matched for age and gender for four seconds per image in a random order.
Like the control adults, the control children had a high response in the middle cingulate cortex when looking at their own pictures. In contrast, children with autism spectrum disorder had a significantly diminished response.
Importantly, the researchers could detect this difference in only a single image. The single-image part is important, Montague points out, as children with autism cannot stay in the scanner for long, so the test must be quick.
“We went from a slow, average depiction of brain activity in a cognitive challenge to a quick test that is significantly easier for children to do than spend hours under observation,” Montague said.
“The single-stimulus functional MRI could also open the door to developing MRI-based applications for screening of other cognitive disorders.
“Also, getting an earlier diagnosis can also have a tremendous impact on the children and their families,” Montague said.
“The younger children are at the time of diagnosis,” Montague said, “the more they can benefit from a range of therapies that can transform their lives.”
Source: Virginia Tech