Oliver Sacks: My way of studying the brain, as a clinical neurologist, is not to stick electrodes in it or to do brain imaging — although, of course, these may be necessary — but to see the impact of various diseases, various forms of damage on the person. One can learn a tremendous — one sees a tremendous amount this way. For example, although we get a sort of seamless picture of the world, there are 40 or 50 sub-systems, visual sub-systems, and one would have no idea of their existence were it not that one or two of them might be knocked out. Someone might become totally color blind or motion blind or something else. So on the one hand, I plot the person’s ability to construct a world, a visual world, a moral world, whatever — intellectual world — on the basis of their brain functions and their compromise. But equally, I’m very much concerned with peoples’ ability to continue life, or to renew themselves or to reconstruct themselves and their lives in other ways, so that even if, let us say, color vision is lost, the black and white world can then become heightened and enhanced. And there may be a heightened sense of contour and boundary and texture and tone and movement and depth and everything else. So for me, this is a way of seeing how people and brains construct worlds and construct selves.