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In 2006 your lab published a paper in Nature Neuroscience linking a mirror neuron dysfunction to autism. How might reduced mirror neuron activity explain the symptoms of autism?

Reduced mirror neuron activity obviously weakens the ability of these patients to experience immediately and effortlessly what other people are experiencing, thus making social interactions particularly difficult for these patients. Patients with autism have also often motor problems and language problems. It turns out that a deficit in mirror neurons can in principle explain also these other major symptoms. The motor deficits in autism can be easily explained because mirror neurons are just special types of premotor neurons, brain cells essential for planning and selecting actions. It has been also hypothesized that mirror neurons may be important in language evolution and language acquisition.

Thus, a deficit in mirror neurons can in principle account for three major symptoms of autism, the social, motor and language problems.

There is convincing behavioral evidence linking media violence with imitative violence. Mirror neurons provide a plausible neurobiological mechanism that explains why being exposed to media violence leads to imitative violence.

I think there are two key points to keep in mind. The first one is the one we started with: mirror neurons are brain cells specialized for actions. They are obviously critical cells for social interactions but they can’t explain non-social cognition. The second point to keep in mind is that every brain cell and every neural system does not operate in a vacuum. Everything in the brain is interconnected, so that the activity of each cell reflects the dynamic interactions with other brain cells and other neural systems.

An initial retrospective study is comparing two groups of 20 children initially diagnosed with autism who were functioning well after two or more years of treatment, either with a discrete trial training approach or the DIR approach. The study aims to determine if treatment differences lead to subtle differences in outcome, for example, in terms of flexibility, emotional range, creativity and richness of the child's inner life. Investigators are planning to follow this research with a prospective, randomized, more rigorous study of the two approaches.

"In our previous studies we found out that it looks like you can't just deliver a standard treatment to autistic kids, that there's so much variability among the children that what works for one child doesn't work for another child," he says. "Our hypothesis is that...unless you individualize treatment, you're not going to get the best effect."

Researchers at the University of Maryland are testing an intervention to trigger children's "social engagement system," which includes behaviors such as listening, looking, facial expressions and vocalizations that support social interaction, says psychologist Stephen Porges, PhD. The treatment is designed to improve autistic children's ability to interact with others, thereby making them more receptive to traditional therapies.

The intervention is based on the theory that tensing the middle ear muscles enables people to pick out the human voice from lower frequency sounds in the environment, Porges says. Treatment involves exercising middle ear muscles by playing music that has been altered to include only frequencies associated with the human voice, which improves one's ability to listen to human voices. This, in turn, stimulates the entire social engagement system, Porges says. About 80 percent of 50 children with autism or other behavioral problems receiving this treatment via five 45-minute sessions in a double blind, randomized controlled study showed marked improvements in listening, language and other communication skills.

In a report last year in the Journal of Autism and Developmental Disorders (Vol. 28, No. 1, p. 15-23) evaluating an intensive home-based discrete trial training intervention, Stephen Sheinkopf, PhD, of the University of Miami and Bryna Siegel, PhD, of the University of California, San Francisco, noted that children receiving an average of only 21 hours per week of treatment showed gains in IQ comparable to those achieved by children receiving 32 hours per week. The intensity question remains an issue of importance for the autism community. "If we need 40 hours a week, fine," says psychologist Geraldine Dawson, PhD, of the University of Washington. "But if you only need 25, you have to realize that 40 hours is a tremendous burden not only financially, but on families and on the child."