I really enjoyed the book, "The Spiritual Doorway in the Brain: A Neurologist's Search for the God Experience." However, when I sat down to read this book (after returning the aforementioned book to the library) it seemed very familiar. So, I compared the tables of contents of the two on Amazon and they were identical. This volume may contain new information, or it may not. I don't have the other book with me, so I can't say for sure. In any case, the first book was good, but I can't tell the difference between that one and the current one.