What biological benefits (if any) does meditation have? Does it work?

Have any medical studies ever been conducted on the effects of meditation, and if so, what did they find?

And what do people meditate on? I mean, is it really picturing a tranquil scene in a forest or is it more of the “just be at one with yourself and empty your mind” shclap?

In short, does meditation really help to decrease responsiveness to stress and stressful situations (as I have heard)?

And if so, why?

Sorry, no scientific data to share, but I do have some personal experience.

The way I have been taught is closer to the “shclap” description than it is to picturing a tranquil scene (and your dismissive tone is duly noted).

We are taught to sit or kneel, with spine straight and hands palm-upward at the juncture of the torso and thighs. The straight spine facilitates deep breathing, and the palms-up posture is a “signal” to the body. Just as students are told to always study in the same place to create a “studious” attitude, the meditation-only posture helps set the tone for the meditation.

Close eyes; breathe deeply from low in the abdomen - this fills the lungs from the bottom, more deeply oxygenating the body. Direct your eyes upward - aim for a spot between your eyebrows. This keeps you from falling asleep, and keeps your eyes from “leading” your body into a drooping posture.

Now the hard part. Clear your mind. Don’t think. When a thought comes, dismiss it without comment. Don’t think about the fact that you aren’t thinking.

(Don’t think about the fact that you’re not thinking about not . . . oh, never mind).

In time, you’re able to achieve a statement of awareness without content. It’s an interesting mental state to be in, and very difficult to maintain. (“Hey! I’m aware! Oh - damn!”) Done correctly, meditation is really, really hard.

Now the benefits (disclaimer - what follows is anecdotal; YMMV). With practice, you find (okay, I found) that you can apply the breathing-and-clearing techniques when you’re not sitting in a quiet place. You can do it in traffic, in meetings - wherever. In physical situations, it enhances alertness and awareness of surroundings, and helps keep your reactions calm(er) and, I think, more quickly responsive. In human interactions, it’s very helpful in tense situations when emotional reactions would be a Bad Thing.

Why does this work? Beats me (yeah, I know - not very helpful, am I?). I just know that if I go too many days without at least twenty minutes of disciplined sitting, the wheels tend to come off a lot more easily.

Lots of studies have been done and it’s probably best to let them speak for themselves:

http://www.google.com/search?sourceid=navclient&q=physical+effects+meditation

The first couple links are for books and most of the studies hedge their answers in the common ways. Basically: Yes, but maybe it’s the placebo effect and maybe not that much and maybe not for you.