Why some autistic kids are painfully sensitive to noise and bright lights

Children with autism see simple movement twice as quickly as other kids of their age, and this hypersensitivity to motion may provide clues to the cause of the developmental disorder, a new study has claimed.

According to Duje Tadin, one of the lead authors on the study and an assistant professor of brain and cognitive sciences at the University of Rochester, such heightened sensory perception in autism may help explain why some people with the disorder are painfully sensitive to noise and bright lights.

Tadin said that it also may be linked to some of the complex social and behavioral deficits associated with autism.

He asserted that people think of autism as a social disorder, as kids with this condition often struggle with social interactions, but what we sometimes neglect is that almost everything we know about the world comes from our senses.

Tadin said that abnormalities in how a person sees or hears could have a profound effect on social communication.

In the study, 20 kids with autism and 26 typically developing children, ages 8 to 17, looked at brief video clips of moving black and white bars and simply indicated which direction the bars were heading, right or left.

Each time a kid made the correct direction choice, the next video clip became slightly shorter and thus a little more difficult.

But when they made a mistake, the next video became a bit longer and thus easier to see, in this way, the researchers were able to measure how quickly children with autism can perceive motion.

The researchers found that when the bars in the image were just barely visible, both groups of children performed identically.

When the contrast or darkness of the bars was increased all participants in the study got better at perceiving the direction of movement.

“But kids with autism, got much, much better—performing twice as well as their peers,” Jennifer Foss-Feig, a postdoctoral fellow at the Child Study Center at Yale University, said.

In fact, the worst performing participant with autism was roughly equal to the average of the participants without autism.

Foss-Feig said that this dramatically enhanced ability to perceive motion is a hint that the brains of individuals with autism keep responding more and more as intensity increases.

She said that although this could be considered advantageous, in most circumstances if the neural response doesn’t stop at the right level it could lead to sensory overload.

The findings have been published in the Journal of Neuroscience.