'Measuring Thoughts' Accurately Detects Autism

Liam Davenport

December 03, 2014

Brain imaging that shows neural representations of social interactions can accurately identify individuals with autism, a finding that may have the potential to revolutionize the diagnosis and treatment of autism and possibly other psychiatric illnesses.

Using functional magnetic resonance imaging (fMRI), investigators at Carnegie Mellon University, Pittsburgh, Pennsylvania, found that individuals with autism lacked neural representations of the self when thinking about social interactions, a pattern that distinguished between individuals with autism and control participants with 97% accuracy.

"This is the first time that anybody has associated an alteration in a particular thought pattern with a psychiatric disorder," lead investigator Marcel Just, PhD, D. O. Hebb Professor of Cognitive Neuroscience, told Medscape Medical News.

"There's social awkwardness in autism, and now we can see the biological basis of the social awkwardness. It has to do with an alteration of how the representation of the self, which is almost missing in people with autism, think about the social interaction. They don't see themselves as part of the concept of hugging or persuading or adoring."

The study was published online December 2 in PLoS One.

Banana or a Chair?

The current findings build on several years' worth of groundbreaking research by Dr Just and colleagues.

"About 6 years ago, my colleagues and I developed a new method that could tell you what a person was thinking from their fMRI activation pattern."

"So, if you thought of a banana or a house or a chair, I could tell by looking at your brain activity. That was a big thing; nobody has ever connected brain activity to specific thoughts before."

"The second extremely interesting part is that these activity patterns were common across people. So when you think of banana, approximately the same activation pattern that you can see on the screen goes on in your brain as in my brain. That means that there are normative patterns of activation to specific concepts...it's common across people," he added.

Dr Just observed that social processing is altered in individuals with autism.

"So the rationale for the study was, If we can detect patterns that are common across people for concepts, and in this case, social concepts, maybe we can find psychiatrically altered patterns in a special population ― people with high-functioning autism," he said.

The team examined brain activation patterns measured from fMRI scans in 17 adults aged 16 to 38 years with high-functioning autism and 17 age- and IQ-matched control participants as they thought about eight social interaction verbs: compliment, insult, adore, hate, hug, kick, encourage, and humiliate.

The verbs were considered from two perspectives (action or recipient), to give a total of 16 social interaction items, which were presented six times. The participants also completed neuropsychological tests. Factor and machine learning analyses were applied to the data.

Present at Birth

The researchers found that individuals with autism lacked a subcomponent of neural activity in the posterior cingulate/precuneus in response to concepts such as hug and adore. In contrast, this activity was strongly present in control individuals.

Machine learning analysis was able to automatically identify individuals with autism and control individuals on the basis of these thought marker patterns on fMRI with an accuracy of 97%, with 33 out of 34 participants correctly identified.

Moreover, an individual's neural representation of a particular social interaction could be reliably identified by a machine learning classifier trained on neural activity patterns from either the same or another individual.

This suggests that there is a systematic relationship between brain activity and thoughts on social interactions that is common across individuals, including those with autism.

Finally, the degree to which the neural representation of the self in individuals with autism is altered correlated both with the quality of the cingulum bundle, which connects regions associated with representation of the self, and with behavior, such as face processing ability.

Dr Just believes that this biological basis of autism is likely present when infants are born.

"At 6 months, you already see abnormalities in the brain tissues," he said, adding, "between 6 and 12 months, you start to see the social abnormalities, like a lack of interest in sharing social experiences with others."

Is Autism Reversible?

Together, these findings raise the intriguing prospect of potentially reversing the social interaction deficits seen in people with autism. To illustrate this point, Dr Just referred to an article by him and a colleague published in 2009 on children aged 8 to 10 years with dyslexia.

After 100 hours' training in word decoding, the participants' reading improved. More importantly, "their white matter in the areas of deficit improved to a normal level, and the amount of improvement in the white matter was correlated with the amount of improvement in their reading performance," Dr Just said.

"[The children] became better myelinated in these areas that had previously been in deficit, and their reading performance improved correspondingly."

"So it’s possible to change children's brains with appropriate remedial techniques. There are ongoing studies now testing to see whether this is possible in autism. It's obvious that it's possible."

In addition to the importance of the current findings to the diagnosis and management of individuals with autism, the imaging techniques employed could have far wider applications.

"Almost all psychiatric illnesses are an alteration of some kind of thought ― for autism, it's social thoughts; but for paranoia, it's thought of persecution; for obsessive-compulsive disorder, it's thought of conscientiousness and making errors," Dr Just explained.

"All of these are in the brain somehow, and now we have a new, independent technique to assess them. It's imaginable that one could have a psychiatric assessment that has a person going into a scanner, thinking about lots of different types of concepts, and seeing which ones are altered and how they're altered."

Interesting, Innovative

Commenting on the findings, Marjorie Solomon, PhD, associate clinical professor of psychiatry and behavioral sciences at the University of California, Davis, welcomed the study.

"This is an interesting study with an innovative design. The author's focus on autistic persons' experience of the self in the context of social interactions is relevant to many areas of everyday functioning and relationships," she told Medscape Medical News.

"The development of the self also is important for promoting mental health and self-esteem. Furthermore, a strong sense of self is instrumental in encouraging adult development ― an area in need of a better treatment armamentarium," Dr Solomon added.

The National Institute of Mental Health funded this research. The authors and Dr Solomon have disclosed no relevant financial relationships.

PLoS One. Published online December 2, 2014. Full article

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