If people with Alzheimer’s have earlier displays of behavioral changes, then how much do we know about where behavior is controlled inside the brain?

That’s a great question. I think in Alzheimer’s disease, the behavior may be quite normal for long periods of time, and in frontotemporal dementia, that’s never the case. In frontotemporal dementia, which begins in the frontal lobes and the anterior temporal lobes, we are seeing bad behaviors, way before memory loss. And the behavior is different from what we see in Alzheimer’s. We see disinhibition. People commit antisocial behaviors and crimes. They are profoundly apathetic, hardly move from in front of a television. They overeat. They develop repetitive motor behaviors, like drinking Cokes over and over again, collecting napkins. The behaviors of FTD are very different from those of Alzheimer’s, and that’s because the anatomy, like you say, is different.