'Theory of Mind', or intentionality, refers to the human ability to interpret and act upon the intentions of others through interpreting their facial displays and other observed behaviour.

Although many parts of our mental activity are highly fluid, and can take place in a neurally unpredictably way, more and more individual standard components of our minds are being identified, often by the use of fMRI to map neural events. The component parts of the Theory of Mind network had already been identified in previous studies.

In the Carnegie study, the researchers asked 12 high-functioning autistic adults and 12 control participants to view animations of interacting geometric figures. The subjects were asked to select the word from several choices that best described the interaction. The control subjects were consistently better than the autistic subjects at inferring the intention from the action.

The researchers used fMRI to measure activation levels in activation levels in several frontal and posterior brain regions to determine the synchronization levels in the Theory of Mind network. The autistic participants' brains showed much lower activation levels than their counterparts in the frontal regions, and synchronization between regions was significantly lower in the group with autism.

"The communication between the frontal and posterior areas of the social brain network is impaired in autism, making it difficult to understand the intentions of others," said the study's senior author, Marcel Just, the D.O. Hebb Professor of Psychology at Carnegie Mellon.

"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."