Thanks for the tip.
This is a new book, by a professor, an actual neuroscientist. I have only skimmed one chapter "Your Brain on Porn", which starts on page 83. Seems really good, full, and is more technical than we get.
He teaches at a Christian college
Search for it on Google books - it has the entire chapter up there. Heck, the whole book may be up there.
Wired for Intimacy: How Pornography Hijacks the Male Brain, By William M. Struthers