Why autistic people see faces differently

People with autism spectrum disorder (ASD) gain different perceptions from peoples' faces as the way they gather information - not the judgement process itself - is different from those without the disorder, says a study.

"The evaluation of an individual's face is a rapid process that influences our future relationship with the individual," said lead author of the study Baudouin Forgeot d'Arc from University of Montreal in Canada.

The study was conducted in collaboration with a team from the Hôpital Robert-Debre in Paris, who recruited 71 individuals, including a control group and an ASD group, without intellectual disabilities.

The researchers presented 36 pairs of photographic and synthetic images to the participants, and evaluated their social judgment by asking them to indicate which emotionally neutral faces appeared "kind" to them.

When photographic images of neutral faces were presented, the judgment of ASD participants was mixed compared to participants in the control group - the choices of the ASD participants were not predictable from one participant to another.

However, the researchers found no difference between the groups when participants were presented with synthetic images, which were nevertheless created based on the characteristics of the photographic images previously shown.

The differences observed when they viewed photographic images suggest that the way they gather information about people's faces is critical.