that explains why adolescents are much more sbelsive, why they're much greater risk takers why their intensity is much greater overall. because they don't have that cognitive control that allows you to model late reactions. >> rose: i'm not sure that's good thing. i'd like to be an adolescent. >> everything has a plus and a minus. >> i'd like to pick up a little bit on one of the ideas that emerges from nora's idea about networks which is that if you think of a brain as a series of fixed areas, each one of which does one thing, well, then if you have damage or a problem you're stuck, it's all over. if you think of a brain as a network of interconnected areas then very often you can think about doing work-arounds. >> compensations. >> you can think about compensating and the brain is incredibly flexible. for everything we know about it, it has the ability often to find some kind of a work-around for some sort of a pre-existing problem. and this is... this happens at large-brain area levels, it happens at microscopic levels. there's a common form of human mental retardation called frag