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Several months ago, Courchesne unveiled results from a brain-imaging study that led him to propose a provocative new hypothesis. At birth, he notes, the brain of an autistic child is normal in size. But by the time these children reach 2 to 3 years of age, their brains are much larger than normal. This abnormal growth is not uniformly distributed. Using MRI-imaging technology, Courchesne and his colleagues were able to identify two types of tissue where this mushrooming in size is most pronounced...
...unlike a computer, does not come into the world with its circuitry hard-wired. It must set up its circuits in response to a sequence of experiences and then solder them together through repeated neurological activity. So if Courchesne is right, what leads to autism may be an otherwise normal process that switches on too early or too strongly and shuts off too late--and that process would be controlled by genes...
...genes that set the stage for autistic disorders could derail developing brains in a number of ways. They could encode harmful mutations like those responsible for single-gene disorders--cystic fibrosis, for instance, or Huntington's disease. They could equally well be garden-variety variants of normal genes that cause problems only when they combine with certain other genes. Or they could be genes that set up vulnerabilities to any number of stresses encountered by a child...
...more scientists ponder such questions, the more it seems they are holding pieces of a puzzle that resemble the interlocking segments of Tommy Barrett's Transformer toys. Put the pieces together one way, and you end up with a normal child. Put them together another way, and you end up with a child with autism. And as one watches Tommy's fingers rhythmically turning a train into a robot, a robot into a train, an unbidden thought occurs. Could it be that some dexterous sleight of hand could coax even profoundly autistic brains back on track? Could it be that...
Neuroimaging studies confirm what scientists long suspected: autistic brains don't react to facial cues the way normal brains do. But in one regard the conventional wisdom was wrong. In a breakthrough study, Karen Pierce at the University of California at San Diego has shown that when faces of strangers are replaced by faces of loved ones, the autistic brain lights up like an explosion of Roman candles...