The relation between cerebral blood flow (rCBF) and the clinical severity of symptoms in 45 autistic children, mean age 7.9 years, was determined at centres in Paris, France. CBF was measured with PET after IV injection of H215O. A global index of autism severity (Autism Diagnostic Interview-Revised [ADI-R]) and indices of stereotypes and repetitive behaviors correlated with rCBF reduction in the left superior temporal gyrus. The more severe the autism, the greater the reduction in rCBF. Social interaction deficits corresponded with dysfunction in the right parietal lobe. 
COMMENT. The superior temporal lobe in the dominant hemisphere represents language functions and may be involved in social interaction . The above study supports the concept of a neurobiological cause for autism, localized to the temporal lobe.