LOS ANGELES — Oxytocin, the "cuddle" hormone that makes mothers' milk flow, men faithful to their mates and even tough negotiators more trusting, also makes children with autism more attuned to social cues in others, a new study says.
The study found that compared with autistic children who got a placebo nasal spray, autistic children who got a puff of oxytocin up the nose responded to pictures of people's faces with greater activation in their brains' "social circuits" and in the regions key to reward and motivation. When an autistic child got oxytocin and was asked to identify images of socially neutral things such as cars and trucks, activity in these social and motivation brain regions were notably less active than they were in those on the placebo.
The study, conducted by researchers at Yale University, was published this week in the journal PNAS.
"These results may imply that oxytocin makes social stimuli more rewarding and socially salient to children with autism spectrum disorder," the authors wrote. Citing oxytocin research on animals, the authors speculated that when a shot of oxytocin hits the autistic brain, it boosts the "signal-to-noise" ratio in regions that make sense of our social world, and makes positive social interaction easier and more pleasant.
When the study's 17 participants were asked to identify the emotion that a pictured face was expressing, oxytocin did not improve their speed or accuracy in answering. But that might change with more practice under oxytocin's influence, the researchers suggested.
With the regions of the brain that are suited to the task of reading social cues working more normally, kids with autism might be able to reverse the cascade of effects that may characterize autism: Those may start as a subtle deficit in social drive and motivation during infancy, prompting these children to interact less, resulting in poorer social skills and brains that develop more and more differently than those of typically developing children.
With oxytocin-aided social skills training, that cascade of developmental differences might be interrupted, or at least blunted, many researchers believe.