Neuropathology of attention and ADHD

Professor Judith Rapoport discusses correlates of attention in the frontal and parietal lobes, which are related to the neuropathology of attention.

Although people think of attention and focusing your efforts as going along with the frontal lobe part of the brain, the psychologists have shown that there are what are called posterior attention systems, too, particularly the right parietal area, there in the back of the brain. And you can ask the computer when you study brain development in hyperactivity, is there any part of the brain that develops differently in hyperactive children than in normal children? Because we have all of these children, hyperactive and not hyperactive, who had a brain MRI scan every two years over about an 18-year period. There’s one part that shows up, only one part, and that’s in this posterior parietal system, which we know from studies with monkeys and studies with normal volunteers, also lights up in some attentional studies. To put this story together, it’s been shown that hyperactive kids as a group don’t use their frontal lobes very efficiently. When they are doing studies, their lobes don’t light up in the functional brain imaging studies the way they should, compared to non-hyperactive kids. So, you put this together and you wonder, maybe it’s because the kids who did well learned to rely more on that posterior parietal, the posterior attention system. So, Philip [Shaw] looked to compare the good outcome and the bad outcome, and the fact that this part was different was accounted for by the good outcome, and this part – the cortex – stayed thicker than you would have predicted, as if it was being used more. So we have this sort of complicated story to suggest that it can be a way that you compensate for getting better and may account for why it is that a third of people get better from the ADHD.