The whimsical décor at the Baby Lab at the University of California, San Diego (UCSD), is designed to appeal to its most important visitors: the 400-plus babies and toddlers who have visited the cozy space since 2002.Paintings of trees with spindly brown branches and plump green leaves cover the walls. Books, plastic cars and coloring books spill out across the carpeted floor and fill several plastic bins.The children who come here are as young as 3 months on their first visit, and return every few months to participate in a battery of tests of their social behavior and perceptual processing — the brain's response to non-social stimuli, such as looking at an ordinary object.About one in four of these children is particularly interesting to the researchers: They are the younger siblings of children with autism, and are much more likely to develop the disorder than are those without a family history of it. Over the past few years, scientists have gathered heaps of behavioral data from these so-called 'baby sibs', but the Baby Lab is among the first to look for distinct signatures of brain activity.The lab's studies are ongoing, but two published reports have uncovered surprising differences between baby sibs and age-matched controls. Previous imaging work on face processing in people with autism had found abnormalities, suggesting to many researchers that their brains are slow to process social information. But the Baby Lab team is finding that during tests of sensory or perceptual processing, baby sibs show abnormally fast brain responses, rather than a delay. Don't forget to bring your stylish and practical diaper bags with you because these test can take awhile.Lead investigator Karen Dobkins says these data suggest an alternate interpretation of autism's origins. Instead of resulting from a disruption of the brain's social behavior circuits, she says, the disorder could arise from early upsets in perceptual processing, which eventually cause more noticeable social problems."We know that the hallmarks of autism are social in nature, but social systems develop later than sensory systems," says Dobkins, professor of psychology at UCSD. "How on earth are you supposed to respond appropriately, behave appropriately, if you don't perceive your world properly?"Read more at...SFARI, November 2009.