Savant syndrome and autism, I think, are not disorders of brain structure, but they're disorders of brain function.
Savant syndrome is not a disorder in the same way as autism is a disorder or dementia is a disorder. Savant syndrome are some conditions that are superimposed and grafted on to some underlying disability. So savant syndrome is not a disease or disorder in and of itself. It is a collection of characteristics, or symptoms, or behaviors that have grafted on to the underlying disability.
Parents don't particularly care whether it's early infantile autism or whatever label the clinicians have put on it. All they want is treatment, and they want what's best for their child, whatever that is. And when it comes to treatment, it may be that there's much more shared interventions that don't make any difference what label we're putting on it.
I think that if I could do any sort of research of autism that I wanted to do, at this point I would take a sample of classic, early infantile autism persons and compare them with what I call "classic late onset autism", individuals. I think we will find that the cause of those youngsters with autism who have autism from birth is probably different than those who have late onset autism.
I think one of the problems with the definition of autism is we keep expanding it. It started as "early infantile autism", and then it became "autism", and now it's "autism spectrum disorder". I'm not opposed to that from the standpoint of trying to broaden our vistas, and so forth. But from a research point of view, the term autism is lost in specificity.
When we come to research, if we want to find out the cause of autism, we're going to have to be much more specific, and that's why when it comes to research, I'm fairly strict with respect to criteria. When it comes to treatment, I'm much more open to not making that differentiation.
The narrower we define autism, and the more strictly we control for particular behaviors, the more likely we are to find what I think are the subgroups of autism.
I have a fairly strict definition of early infantile autism. That is not to say that people who don't meet that classic description don't have autism, but we might do well to narrow our definitions, and our samples, down to groups that are very similar, because I think you're more likely to find the cause.