Mirror neurons fire when a person performs a goal-directed action and while he or she observes the same action performed by others. Neuroscientists believe this observation-execution matching system provides a neural mechanism by which others' actions, intentions and emotions can be understood automatically.
Symptoms of autism include difficulties with social interaction -- including verbal and nonverbal communication -- imitation and empathy. The new findings dramatically bolster a growing body of evidence pointing to a breakdown of the brain's mirror neuron system as the mechanism behind these autism symptoms.
"Our findings suggest that a dysfunctional mirror neuron system may underlie the social deficits observed in autism," said Mirella Dapretto, lead author and assistant professor in residence of psychiatry and biobehavioral sciences at the Semel Institute for Neuroscience and Human Behavior at UCLA and the David Geffen School of Medicine at UCLA. "Together with other recent data, our results provide strong support for a mirror neuron theory of autism. This is exciting because we finally have an account that can explain all core symptoms of this disorder."
Conducted at the Semel Institute's Ahmanson-Lovelace Brain Mapping Center, the research used functional magnetic resonance imaging (fMRI) to measure brain activity in 10 high-functioning children with autism while they imitated and observed 80 photos depicting different emotions such as anger, fear, happiness or sadness. In addition, the brain activity of 10 typically developing children was studied while performing the same tasks.