The first three books listed at http://www.xenodochy.org/gs/readinglist.html include quite a bit about neuro-physiological mechanisms that affect our thinking, etc., as these empirically discoverable processes appear to work as analyzed by recent science. You also might want to keep up on the Scientific American publication Mind http://www.sciammind.com/ It's clear that we don't know enough yet, and that seems born out by the widely ranging comments above.