Jundo made some very interesting points when talking about the neuroscience stuff. In fact, he hit on something that to me is essential.
I have a vascular malformation in my brainstem, which causes a variety of symptoms because of blood, following a bleed, that doesn't get reabsorbed, and is an irritant. This led me, about a year and a half ago, to get back into meditation, after a long hiatus, and, at the same time, to try and learn more about the brain. I noticed, for example, that when meditating long enough, some of my physical symptoms would fade away. I knew this was not that I had ignored them, because they are physical symptoms, not merely mental constructions that lead to physical sensations.
So I looked into this (notably with this astounding, though dense, book, Zen and the Brain - ). It turns out that meditation can affect levels of gamma-aminobutyric acid (GABA) in the brain, and that GABA is the main inhibiting neurotransmitter. Interestingly, the medication I take attempts to stimulate GABA production or enhance GABA neuroreceptors. That's the principal of most anti-epileptic or anti-convulsant medication. It slows you down a bit, but that slowing down prevents the brain from going into overdrive. (Obviously, that's not the only brain chemical affected by meditation.)
So why is this important? It showed me that meditation is not about faith or religion; that meditation is, or should be, first and foremost looked at as a "technique". I hesitate to say a "self-improvement" technique, because of the connotations of that term, but it allows me to look at meditation without "spirituality", which often suggests superstition. This fits with much of what Jundo says, such as how the Buddha was "just an ordinary guy", and all that, and it reassures me, because I'm not looking for faith - a blind acceptance of something - but rather experience.
Interestingly, I came across this article in today's science news, about how yoga increases GABA:
http://www.sciencedaily.com/releases/20 ... 145516.htm
They're looking at medical applications there, but I think the point remains that meditation does things, not just in the mind, but in the brain as well.