From a young age, children with autism have an altered perception of biological motion - an ability that assists interaction with other living beings and is linked to social understanding. The finding in Nature suggests that this may have an effect on their social interaction in later life.
Biological motion perception has been demonstrated in many species, including humans, and its neural mechanisms are linked with the ability to make social decisions using clues from facial expressions and gaze direction, for example. Ami Klin and colleagues suggest that this perceptual ability may be absent from children with autism.
The team tested two-year-olds with autism against controls of the same age for attention patterns when watching displays of biological motion, such as animations of playing peek-a-boo, in a normal and altered format. They found that the children with autism failed to consistently look at the displays, but were instead attracted to features such as associated noises that were ignored by the control children. This suggests that they are highly sensitive to non-social physical cues, and could explain why children with autism fail to look into people's eyes and focus more at the mouth area.
The autistic children also paid more attention to the display when it was inverted and played in reverse - a format that has been shown to be processed by different circuits in the brain from the perception of biological motion. This suggests a possible disruption of an important mechanism of social interaction.
Data from this study provide a new insight into how children with autism experience the world around them, especially during their first few years of life.
Ami Klin (Yale University School of Medicine, New Haven, CT, USA)
Abstract available online.
(C) Nature press release.
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