This study just came out showing that Zen meditators had thicker areas of the brain associated with pain sensitivity (the anterior cingulate) when compared with non-meditators.
One of the researchers explained: “The often painful posture associated with Zen meditation may lead to thicker cortex and lower pain sensitivity.”
He suggests that it’s the posture that may lead to this brain change.
I’m wondering what vigorous exercise does to this part of the brain, and especially what the combination of meditation with exercise (i.e. Ashtanga yoga) might have on the brain. Maybe having a certain amount of regular voluntary pain increases our threshold, enabling us to withstand higher levels (back to the hormesis idea).