WEDNESDAY, 8 SEPTEMBER 2010
Pierce et al took 110 toddlers (age 14 to 42 months). Some of them had autism, some had "developmental delay" but not autism, and some were normally developing.
The kids were shown a one-minute video clip. One half of the screen showed some kids doing yoga, while the other was a set of ever-changing complex patterns. A bit like a screensaver or a kaleidoscope. Eye-tracking apparatus was used to determine which side of the screen each child was looking at.
What happened? Both the healthy control children, and the developmentally delayed children, showed a strong preference for the "social" stimuli - the yoga kids. However, the toddlers with an autism spectrum disorder showed a much wider range of preferences. 40% of them preferred the geometric patterns. Age wasn't a factor.
This makes intuitive sense because one of the classic features of autism is a fascination with moving shapes such as wheels, fans, and so on. The authors conclude that
A preference for geometric patterns early in life may be a novel and easily detectable early signature of infants and toddlers at risk for autism.
But only a minority of the autism group showed this preference, remember. As you can see from the plot above, they spanned the whole range - and over half behaved entirely normally.
There was no difference between the "social" and "geometrical" halves of the autism group on measures of autism symptoms or IQ, so it wasn't just that only "more severe" autism was associated with an abnormal preference.
They re-tested many of the kids a couple of weeks later, and found a strong correlation between their preference on both occasions, suggesting that it is a real fondness for one over the other - rather than just random eye-wandering.
So this is an interesting result, but it's not clear that it would be of much use for diagnosis.