"Why We Believe What We Believe", co-authored with Mark Robert Waldman (Executive MBA Faculty, Loyola Marymount University) describes the relationship between the brain and beliefs and also describes brain imaging studies of an atheist and individuals speaking in tongues (or glossolalia).A more recent book, "How Enlightenment Changes Your Brain", also co-authored with Waldman, is a scientific and practical look at how faith and meditation can enhance brain function.