How children respond to movement could provide an early means of detecting autism, a new study says.

Children with autism are known to prefer watching repetitive movements over random movements, researchers said.

Using eye-tracking methods, a research team found that children with suspected autism spent longer watching repeated movements than random ones, when both were shown side-by-side.

A brief, two-minute video observation task during childhood check-ups could help identify kids at risk for autism as early as 3 years of age, researchers concluded.

“This approach could be particularly valuable for children who remain underdiagnosed until later childhood, providing a more efficient method for early detection,” researcher Mikimasa Omori, an associate professor at Waseda University in Japan, said in a news release.

For this study, Omori compared 17 children with potential autism and 11 typically developing children.

Participants were shown videos of six geometric shapes — circles, triangles, squares, crosses, stars and octagons.

On one half of the screen, the shapes were traced in a single-stroke predictable motion. On the other side, the shapes were drawn in a random, unpredictable sequence.

Eye trackers found that typically developing children spent about the same amount of time observing both the predictable and unpredictable sides of the video.

But children with suspected autism spent more time watching the predictable image, with results showing that their interest in that side of the screen increased during the test.

“This study revealed that children with potential ASD spent significantly more time observing predictable movements,” Omori said.

This preference for predictable movements jibes with the repetitive behaviors that are characteristic of autism, researchers said.

Currently, early detection of autism focuses on social communication problems like eye contact and language delays, researchers said.

Adding a test that leans on this preference for predictable movements could add another diagnostic tool to the autism toolbox, Omori said.

Because the test doesn’t require a verbal response, it could be adapted for kids younger than 18 months, Omori added.

“This study highlights the potential utility of predictable movement stimuli as a behavioral marker for early ASD screening and underscores the essential need for further research into predictive processing in children with ASD,” Omori said.

Future studies should test this approach in younger and older children, to further prove its effectiveness, researchers said.

The study appears in the journal Scientific Reports.

More information

The U.S. Centers for Disease Control and Prevention has more on diagnosis of autism spectrum disorder.

SOURCE: Waseda University, news release, April 8, 2025