I second this. I just finished this book and it was excellent - however the edition I read is called "The science of mediation". They're very honest about which studies provide robust evidence and really quantify what the benefits of meditation are. They also delved into the 4 "neural pathways" meditation transforms. I've been meditating for 3.5 years and it was a real eye opener reading about how the different techniques I use affect different parts of my brain.

A highly recommended read!