nancy andreasen, m.d., ph.d, in the m.r.i. at the university of iowa hospital center. >> the principle here is that this is what we call the control task. >> woodruff: it's here where she has done groundbreaking neuro- imaging research, especially on schizophrenia, linking it to physical differences in the brain itself. it's something she's been interested in since she received her degree in 1960's. >> i knew i was going to be interested in the brain, because i knew it was the organ that makes us human. >> woodruff: but she's also always had a parallel interest in literature, which led to an unusual field of scientific inquiry: why have so many great writers suffered from mental illness? >> i knew that for instance bertrand russell, great philosopher, had a family just loaded with schizophrenia. james joyce, had a daughter with schizophrenia and joyce himself was also kind of odd. >> woodruff: in the 1960's and '70's, she took advantage of the university's nationally renowned iowa writer's workshop to study writers who taught