When we have a conversation with someone, we not only hear what they say, we see what they say. Eyes can smolder or twinkle. Gazes can be direct or shifty. Reading these facial expressions gives context and meaning to the words we hear.
In a report to be presented May 5 at the International Meeting for Autism Research in Seatlle, researchers from UCLA will show that children with autism cant do this. They hear and they see, of course, but the areas of the brain that normally respond to such visual cues simply do not respond.
Led by Mari Davies, a UCLA graduate student in psychology, and Susan Bookheimer, a professor of psychiatry and biobehavioral sciences at the Semel Institute for Neuroscience and Human Behavior at UCLA, the research compared brain activity between 16 typically developing children and 16 high-functioning children with autism. While undergoing functional magnetic resonance imaging (fMRI), both groups were shown a series of faces depicting angry, fearful, happy and neutral expressions. In half the faces, the eyes were averted; with the other half, the faces stared back at the children.
With the typically developing group, the researchers found significant differences in activity in a part of the brain called the ventrolateral prefrontal cortex (VLPFC), which is known to play a role in evaluating emotions. While these children looked at the direct-gaze faces, the VLPFC became active; with the averted-gaze pictures, it quieted down. In contrast, the autistic children showed no activity in this region of the brain whether they were looking at faces with a direct or an indirect gaze.
This part of the brain helps us discern the meaning and significance of what another person is thinking, Davies said. When responding to someone looking straight at you, as compared to someone whos looking away, the brain discerns a difference. When the other person looks away, the brain quiets down.
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Contact: Mark Wheeler
mwheeler@mednet.ucla.edu
310-794-2265
University of California - Los Angeles
5-May-2007