The pat-a-cake animation, with color scaled values showing the level of audiovisual synchrony at each point-light.  Dark blue values correspond to little or no audiovisual synchrony; red corresponds to the highest level of synchrony.


Most young animals, from newly hatched chicks to 2-day-old humans, are exquisitely sensitive to the movements of other animals. But 2-year-old children with autism don’t pay special attention to this so-called ‘biological motion’, according to a study published today in Nature.

Unlike healthy children of the same age, toddlers with autism show no preference for scenes of a purely social nature — such as the waving arms and cooing noises of an adult playing ‘peek-a-boo’ — compared with the same scenes shown upside down.

Children with autism instead pay more attention to scenes in which large movements are perfectly synchronized with loud noises, such as the pronounced hand claps of a ‘pat-a-cake’ game, the study found.

In contrast, healthy toddlers always favor biological motion: they look at the upright scenes more than the upside-down scenes, regardless of whether the scenes contain high levels of audio-visual synchrony.

That children with autism have heightened sensitivity to audio-visual synchrony “really caught us by surprise,” says lead investigator Ami Klin, director of the Autism Program at the Yale Child Study Center.

These results may explain an earlier report by Klin’s team that unlike healthy children, who fixate on other people’s eyes, 2-year-olds with autism prefer to look at their mouths.

“The question was, why in the world would people with autism focus on the mouth? And now [Klin] has got a really neat answer: the mouth is a place where sound is synchronous with the motion of the lips,” says Maggie Shiffrar, professor of psychology at Rutgers University in New Jersey.

“Now that they’ve identified what people with autism are really good at, it’s a huge advance because you can design treatments that take advantage of that,” Shiffrar adds. For instance, researchers could design behavioral treatments that pair audio-visual synchrony with important social information.

The study suggests that in children with autism, certain brain mechanisms diverge from the normal path very early in development, says Klin. Children who don’t have the ability to process social information may rely on these ‘physical contingencies’, such as audio-visual synchrony, to learn about the world.

The precise timing of developmental divergence could account for the diverse spectrum of behaviors on the autism spectrum — an idea that Klin is testing by looking for impairments in biological motion perception and other measures of social engagement in infant siblings of children with autism.

…Read the rest of my latest article from SFARI