Children with Autism Have An Error in Their Mirror Neuron System

Children with autism have virtually no activity in a key part of the brain's mirror neuron system while imitating and observing emotions, the University of California researchers concluded.

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.

"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 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."

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.

The study shows that unlike typically developing children, children with autism have virtually no activity in a region of the brain identified by previous research as a key part of the mirror neuron system. Importantly, the level of mirror neuron activity seen in children with autism was inversely related to symptom severity in the social domain.

Children with autism also showed reduced activity in the emotion centers of the brain, consistent with the hypothesis that this mirroring mechanism may play a crucial role for understanding how others feel and for empathizing with them.

Functional MRI is based on the increase in blood flow to the local vasculature that accompanies neural activity in the brain.