Yale researchers have for the first time used functional MRI to study brain organization in persons with autism and Asperger Syndrome and found that they perceive faces as if they were objects.
"This may be a result of a lifelong disinterest in people, and a failure to develop normal expertise for faces," said Robert Schultz, the study's principal investigator and director of the Neuroimaging Research Program in Autism at Yale.
The three-year study resulted in the discovery of reduced activation in the fusiform gyrus -- the classic face area of the cerebral cortex. Researchers also observed increased activation in an adjacent region of the brain that processes non-face objects.
Autism and a closely related condition, Asperger Syndrome, are characterized by impairments in social functioning and interactions. Difficulty recognizing other people by their faces is also one of the characteristics of these disorders.
"This finding is very compelling since it fits with our clinical experience of autism," Schultz said. "Persons with autism and Aspergers have very little interest in people, and our study shows that this disinterest is reflected in the manner in which the visual processing centers are organized in their brains. We cannot know at this point whether this difference in brain organization and function is at the heart of the cause of autism and related disorders or whether it is merely a reflection of what happens to the brain during early development when a person has autism or Asperger Syndrome."
"Of the things that the developing child routinely encounters, the human face is probably the most frequent and important," said Schultz. "The ability to recognize and remember people by their face is critical for all types of interpersonal relationships. The face conveys many important types of information, including a person's age, sex and emotional state. Decoding this information is critical to successful functioning within a group. It is precisely these things that are so difficult for these patients."
Unlike the typically developing child, the child with autism will have much less frequent exposure to people and social interactions, with much less actual processing time devoted to people and to the large range of emotions and social behaviors that humans typically exhibit. This atypical set of formative experiences occurs when the brain is still quite malleable.
"Thus, it is possible that what we have observed with MRI in a predominantly young adult sample is the outcome of having autism or Asperger Syndrome, an outcome born from many years of abnormal experiences with the social world," Schultz said.
"Our results have direct implications for early intervention with social training for persons with Asperger Syndrome, while the brain is still malleable, and capable of developing more normally," said Schultz. "Direct intervention for very young children with social disabilities could have a beneficial effect on the development and organization of their brains."
In addition to Schultz, researchers from the Yale Child Study Center and the Department of Psychology and Diagnostic Radiology contributed to the study. They include Isabel Gauthier, Ami Klin, Robert K. Fulbright, M.D., Adam W. Anderson, Fred Volkmar, M.D., Pawel Skudlarski, Cheryl Lacadie, Donald J. Cohen, M.D., and John C. Gore.