The study, involving 13 adults with either a high-functioning form of autism or Asperger syndrome, a mild form of the disorder, found that when the subjects inhaled the hormone oxytocin, they scored significantly better on a test that involved recognizing faces and performed much better in a game that involved tossing a ball with others.

Although more research is needed to confirm and explore the findings, the results are the latest in a growing body of evidence indicating that the hormone could lead to ways to help people with the often devastating brain disorder function better.

"This is the first study that looked at whether oxytocin has an effect on social behavior, which is a major deficit in autism," said Angela Sirigu, who directs the National Center for Scientific Research in France and led the study, published online by the Proceedings of the National Academy of Sciences. "It looks like it could be very helpful."

Researchers who were not involved in the study praised the work, saying the findings were promising and could lead to the first effective treatment for the central problems affecting people with autism.

"I think it's going to be a very exciting finding for a lot of people," said Alex Martin, chief of cognitive neuropsychology at the National Institute of Mental Health.

Because oxytocin does not last long in the body and produces its effects for a relatively brief period, some experts said the findings were more likely to encourage drug companies to develop alternative substances that had the same benefits.