wolfram schultz, he studies how the brain's reward systems affect decision making and learning. he is a professor of neuroscience at cambridge university and a fellow of the royal society. nora volkow. her research into addiction helps us understand drug abuse as a disease rather than a moral weakness. she is a director of the national institute of drug abuse in washington, d.c. eric nestler. through research on mice, his work has illuminated the molecular basis of drug addiction. he is chairman of the department of neuroscience and director of the brain institute at mount sinai medical center here in new york. and once again, my co-host is dr. eric kandel. he is a nobel laureate, as you know by now, also a professor at columbia university and a howard hughes medical investigator and, as you also know, a great friend of this series and the man who has helped us understand this miraculousar gan. welcome. >> mesh pleasure to be here, as ways. >> rose: so as we go through this. as we have gone from understanding visual perception and understanding the developing brain and the aging