just because i rarely ever see someone appreciating this topic i will share a little experience i had.
i was able to concentrate on my left and right cheeks one night and produced a very acute feeling of pain/itch on both and maintained it till i got bored. i never read or looked into any techniques about this, all i do currently is meditation.
by the way, i think even more impressive than what you mentioned is how swami rama(yogi) was able to maintain a difference of 10C in two adjacent tissues of his hand, they can control arteries/veins individually. he could also stop his heart and lungs for 17 seconds. i read somewhere about another yogi doing it for a solid 3 minutes.
this seems all but a scratch on the surface of what we can do.