I was definitely wary when I started getting into meditation. Walking up to the relevant shelf at Borders, it can look like a bunch of aging hippies and new age

I was definitely wary when I started getting into meditation. Walking up to the relevant shelf at Borders, it can look like a bunch of aging hippies and new age woo. Which is normally a big GET AWAY sign for me. One thing I found useful was the book "Zen and the Brain" by Dr. James H. Austin, published by MIT Press. Austin is an emeritus professor of neuroscience, and has been practicing Zen since he spent some time in Japan in the late 60s. The book is a massive, thousand page, dense doorstop, with lots of information. He tries to come up with possible explanations of the phenomena experienced in meditation, and for how meditation can cause long-term changes. The Table of Contents even includes a listing of chapters with "Testable Hypotheses". The book goes through other phenomena similar to those experienced in meditation, which are caused by known influences such as drugs or localized tissue damage. If I recall correctly, his main idea for how meditation might cause long-term changes in behavior is excitotoxic action of glutamate, etching away certain neural connection pathways.