Eye Contact May Trigger Threatening Signals in Brains of Autistic Children |
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Children with autism may shy away from eye contact because they perceive even the most familiar face as an uncomfortable threat, according to a report in the March 6 online Nature Neuroscience, which detailed two separate, but related, studies. Tracking the correlation between eye movements and brain activity, Kim Dalton, PhD, and colleagues found that the amygdala shows activation to an abnormal extent in children with autism when they are directly gazing at a nonthreatening face. The researchers also reported that because autistic children avert eye contact, the brain’s fusiform region, which is critical for face perception, is less active than it would be during a normally developing child’s stare. “Activation in the fusiform gyrus and amygdala was strongly and positively correlated with the time spent fixating the eyes in the autistic group ... suggesting that diminished gaze fixation may account for the fusiform hypoactivation to faces commonly reported in autism,” the investigators noted. “In addition, variation in eye fixation within autistic individuals was strongly and positively associated with amygdala activation across both studies, suggesting a heightened emotional response associated with gaze fixation in autism.” Dr. Dalton believes that these findings increase the understanding of how the brain functions in an autistic child and that they may one day lead to new treatment approaches as well as help teachers to interact better with their autistic students. “This is the very first published study that assesses how individuals with autism look at faces while simultaneously monitoring which of their brain areas are active,” said Dr. Dalton, Assistant Scientist at the University of Wisconsin–Madison’s Waisman Laboratory for Brain Imaging and Behavior. EVIDENCE IMPLICATES THE AMYGDALAThe study overturns the existing notion that autistic children struggle to process faces because of a malfunction in the fusiform area, noted senior author Richard Davidson, PhD, Professor of Psychiatry and Psychology at the University of Wisconsin–Madison. Rather, in autistic children, the fusiform gyrus “is fundamentally normal” and shows only stunted activity, because overaroused amygdalas make autistic children want to look away, he said. “Imagine walking through the world and interpreting every face that looks at you as a threat, even the face of your own mother,” said Dr. Davidson. Scientists have in the past speculated that the amygdala—which has been implicated in certain anxiety and mood disorders —plays a role in autism, but the study directly supports that idea for the first time. AUTISM AND MRI FINDINGSDr. Dalton’s group conducted two separate studies that used eye tracking while measuring functional brain activity during facial discrimination tasks, both in children with autism and in subjects who were developing normally. In the first study, the researchers placed autistic children inside an MRI scanner and showed them pictures of faces with both emotional and neutral expressions. The children had to press one of two buttons to indicate whether a face was blank or expressive. Throughout the process, the investigators used eye-tracking technology to determine exactly which parts of the face participants were looking at and for how long. Normally developing children far outpaced children with autism in correctly identifying expressions. In the second study, the researchers again showed subjects photographs of both familiar and unfamiliar faces. Using MRI, they monitored the eye movements and brain activity of the children; again, autistic subjects performed considerably worse than did normally developing participants. Autism greatly weakens the capacity to socialize and communicate normally, and the tendency to avoid eye contact is one of the most pervasive traits among autistic children, noted Dr. Dalton. The characteristic is a problem, because eyes, in particular, are a crucial source of “subtle cues that are critical for normal social and emotional development,” she said. FUTURE RESEARCHThe findings could help researchers “train autistic children to look at a person’s eye region in a more strategic way, like when the person may not be looking directly at them,” said Dr. Davidson. Researchers eventually could assess whether such approaches improve the ability to make eye contact and whether they might even induce positive developmental changes in the brain. The study could also lead to further research into the genetic mechanisms underlying hyperactive amygdalas — “a completely uncharted research territory,” added Dr. Davidson. Also, if the autistic amygdala is found to be overactive from infancy, the knowledge could help doctors implement intervention approaches from an early age, he added.
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The following Children Succeed games specifically target the delays found with autism: 
