the next slide will show you what broca and wernicke saw. the left is broca's area and the right is we wereky's area. so it's possible to close off one area and have a broca's syndrome and erexp aphagia or close off blood flow to the posterior and have a receptive aphagia, not understanding the words spoken. so stroke is a huge problem. on a more chronicasis, the degenerative disease i want to mention is parkinson's. if you show the next slide, the part of the brain is deep in the brain, in the brain stem called the substania nigra and they make the neurotransmitter dopamine. these cells degenerate long before, years before there are any symptoms of parkinson's disease. before the faint tremors noted in the hand or stooped posture or slowness to initiate movement. but what i just want to mention that is really the subject of much study at the national institute of neurological disorders and stroke at the n.i. is epilepsy. and here for reasons that are many, the nerve cells are just firing, discharging impulses out of control. and if you see

even though they are not physically located in wernicke and broca. so that understanding of the network architecture of the brain is something that has changed dramatically. brain of children and adolescents is different than the brain of adults. not better, just different. one of the ones that is more fundamental is the connectivity. the brain of the adult is much more cnected than the brain of an adolescent. that doesn't mean it works worse works differently. so for example a dhaex is not fully formed, your differental cortex with your limbic brain and that connection that allows me to literally control the activity of the amygdala is not fully formed until you are in your 20s. that explains why adolescents are much more sbelsive, why they're much greater risk takers why they're intensity is much greater. because they don't have that cognitive control that allows you model late reactions. >> rose: i'm not sure that's a good thing. i'd like to go back to being an adolescent. >> everything has a plus and minus. >> i'd like to pick up a little bit on