structure, with your neurochemistry that can cause disease states later in life. and there are some things that can be changed, and there are some things that are somewhat fixed in the brain. i mean, we know that behavioral interventions can give great results, because like we were talking before, the ability of the brain to adapt, there are some things that you have to kind of hit in the right developmental period before they get pretty well set. >> larry: can you spot this in a 3-year-old? >> i think we're starting to see that with autism, for example. which used to be diagnosed around age, what, 4 and 5. we can see changes in their brains as early as 1 1/2 years old, because they're starting to realize that autistic boys generally have much larger brains than non-autistic boys and now we can measure for those types of things. i think there are some organic things that can be measured early. but oftentimes the behavior has to come out before somebody can