Autistic Toddlers Blink Differently; Finding Could Provide Treatment Clues
(EmaxHealth) New Haven, CT - While blinking is something you do every day and don’t even realize it, the small action in young children is actually a clue to the presence of a developmental delay. Researchers at the Yale Child Study Center observed several children watching videos and noticed that those diagnosed with an autism spectrum disorder had different blink patterns than those who were developing normally.
The American Academy of Pediatrics includes “doesn’t blink when shown a bright light” as a possible sign of developmental delay during the first months of a baby’s life. In fact, blinking rate has been known to be affected by such health conditions as Parkinson’s disease and schizophrenia. While blinking primarily is an essential function that provides moisture to the eye and helps to remove irritants from the surface, the rate of blinking is actually determined by a part of the brain known as the globus pallidus.
People often blink less when the eyes are focused on an object for an extended period of time. During the day, adults blink about 10 times per minute, resulting in about 44 minutes with their eyes closed. But this rate when reading or watching television, for example, is decreased to about 3 to 4 times per minute.
Sarah Shultz, a graduate student at the Yale Child Study Center, studied 93 two-year-old children, some that were typically developing and some with a diagnosis of autism. The kids watched short videos and the researchers tracked when and how often they blinked. As expected, all of the children blinked fewer times while watching the shows.
However, during an emotional exchange between the characters on the video, the children who were developing normally appeared more focused – ie, they blinked less. The autistic children blinked less when there were physical objects in motion, such as when a wagon door was being slammed.
"We have a new way of understanding not just what people are looking at but how engaged they are with what they're looking at," said senior study author Warren Jones PhD, director of research at the Marcus Autism Center and an assistant professor in the department of pediatrics at Emory University School of Medicine in Atlanta.
When you blink, you "lose" a bit of information, Jones added. Therefore, not blinking is a sign that kids find that information most important, engaging or relevant. Prior research has found that kids with autism pay less attention to social cues and social information. "What these new findings and new measure really gives us is an opportunity to look at in more detail how kids with autism are engaging in whatever it is they are looking at," he said.
Rebecca Landa, director of the Center for Autism & Related Disorders at Kennedy Krieger Institute, said the study uses a novel technique to examine how kids with autism process information and respond to things they see. "The more evidence that we have about the nature of the information that children with autism are either delayed in deciphering -- in this case, through visual pathways -- or that they have certain preferences or biases for, the more informed we can be in the development of interventions."
Geraldine Dawson, PhD, the chief science officer for Autism Speaks, is also encouraged by the study findings. “These results suggest that therapy should focus on helping the child to become more emotionally engaged with the social world and to learn that people are important and rewarding.” she says in an email to WebMD. “The hope is that, as a result of therapy, the young child with autism will show higher levels of attention.”
Shultz S, Klin A, Jones W. Inhibition of eye blinking reveals subjective perceptions of stimulus saliencePNAS 2011 ; published ahead of print December 12, 2011,doi:10.1073/pnas.1109304108
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