Autism's social struggles due to disrupted communication networks in brain

While the study participants were performing the task, the researchers used functional magnetic resonance imaging (fMRI) to measure activation levels in all of the cortical areas that compose the ToM network. Specifically, they simultaneously examined activation levels in several frontal and posterior brain regions to determine the synchronization levels in the network. The synchronization was reliably lower in the group with autism.

Furthermore, the autistic participants' brains showed much lower activation levels than their counterparts in the frontal regions. These measures of brain activity in autism, such as the activation level in the posterior part of the ToM network (located approximately behind one's right ear), were correlated with how well each autism participant performed in the Happe's Strange Story Test — a pencil-and-paper assessment of an individual's understanding of non-literal statements, such as figures of speech.

"This study offers compelling evidence that a lack of synchronization in the Theory of Mind network is largely responsible for social challenges in autism," said Just, director of Carnegie Mellon's Center for Cognitive Brain Imaging. "That evidence can provide the foundation for therapies that are more useful than current approaches."

The findings have the potential to guide the development of theoretically based interventions for autism that could target this particular shortfall, for example, by focusing on games and activities that would strengthen the connections. Eventually, it might be possible to tailor autism therapies to the brain communication deficit on a case-by-case basis. Measuring the connectivity before and after an intervention also could be used to determine effectiveness.

The research was supported by a Collaborative Program of Excellence in Autism grant from NICHD and the Cure Autism Now grant awarded to the study's lead author, Rajesh K. Kana, now an Assistant Professor of Psychology at the University of Alabama at Birmingham.

Additional study co-authors include Timothy Keller, Ph.D. and Vladimir Cherkassky, Ph.D. of Carnegie Mellon and Nancy J. Minshew, M.D. of the University of Pittsburgh School of Medicine.